This PDF file contains the front matter associated with SPIE Proceedings Volume 10702, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

The Paranal Instrumentation Programme is responsible for planning and delivering the instruments and the associated infrastructures needed to keep the VLT and La Silla Observatories at the forefront of ground-based astronomy. With the commissioning of the Adaptive Optics Facility (AOF), ESPRESSO, and the two VLTI instruments GRAVITY and MATISSE, all second generation VLT instruments have been brought to the observatory and are close to completion. All these instruments and facilities are offered to the users. By keeping the foreseen roadmap (start one new instrument or upgrade every year), the programme is now completing the CRIRES upgrade and the AO systems for the four VLTI Auxiliary Telescopes (NAOMI), integrating the two MOS Instruments MOONS and 4MOST, as well as the AO infrared imager and IFU ERIS. The strategy for la Silla is to dedicate the 3.6m telescope to exo-planet science, by adding the NIRPS spectrograph to the existing HARPS; and to dedicate the NTT to transient science thanks to the new instrument SOXS. Finally, the programme launched a Call for Proposal to study a visible AO imager 7 spectrograph for the Nasmyth focus of the AOF.

We present an overview of the current status of facility instruments at the Large Binocular Telescope (LBT). These include Optical and Near-Infrared instruments: the prime-focus optical Large Binocular Cameras (LBCs); the optical Multi-Object Double Spectrograph (MODS); and the LBT Near-IR Spectroscopic Utility with Camera Instruments (LUCIs). Each side of the telescope contains one of the aforementioned instruments. We detail the recent move to “all binocular all the time” science operations, including the use of multi-mode Adaptive Optics with the LUCIs (diffraction limited over a 30" x 30" field of view or enhanced seeing over a 4' x 4' field of view). Binocular science has three configurations: Duplex mode, with identical configurations on both sides, providing an effective collecting area of 11.9 meters; Fraternal Fraternal Twin or Mixed mode (same instruments with different setups or different instruments on each side, respectively), which is effectively two 8.4 meter telescopes; or interferometry with a 22.6 meter baseline.

Gemini's instrumentation and adaptive optics development efforts continue to grow. We run an active upgrade program for existing instruments, a facility program to bring new instruments to the observatory, and a visitor program that allows teams to bring their own instruments to Gemini for their own and general community science. On the upgrade front, we have finished installing new CCDs into both our GMOS instruments; improved the capabilities of our multi-conjugate adaptive optics system at Gemini South, GeMS; and replaced the lasers in the adaptive optics systems at both our telescopes. GHOST, our new high-resolution optical spectrograph is nearing completion for 2019 delivery and our new 8-band, optical to infrared imager and spectrograph, OCTOCAM, is well into its design phase. Our visiting instruments continue to grow in both number and complexity and we are developing a path to transition selected instruments from our visitor program to become full facility instruments.

Since the start of operations in 1993, the twin 10 meter W. M. Keck Observatory telescopes have continued to maximize their scientific impact and to produce transformative discoveries that keep the observing community on the frontiers of astronomical research. Upgraded capabilities and new instrumentation are provided though collaborative partnerships with Caltech and UC instrument development teams. The observatory adapts and responds to the observers’ evolving needs as defined in the observatory’s strategic plan, periodically refreshed in collaboration with the science community. This paper summarizes the performance of recently commissioned infrastructure projects, technology upgrades, and new additions to the suite of instrumentation at the observatory. We will also provide a status of projects currently in the design or development phase, and since we need to keep our eye on the future, we mention projects in exploratory phases that originate from our strategic plan. Recently commissioned projects include telescope control system upgrades, OSIRIS spectrometer and imager upgrades, and deployments of the Keck Cosmic Web Imager (KCWI), the Near-Infrared Echellette Spectrometer (NIRES), and the Keck I Deployable Tertiary Mirror (KIDM3). Under development are upgrades to the NIRSPEC instrument and adaptive optics (AO) system. Major instrumentation in design phases include the Keck Cosmic Reionization Mapper and the Keck Planet Finder. Future instrumentation studies and proposals underway include a Ground Layer Adaptive Optics system, NIRC2 upgrades, the energy sensitive instrument KRAKENS, an integral field spectrograph LIGER, and a laser tomography AO upgrade. Last, we briefly discuss recovering MOSFIRE and its return to science operations.

The Advanced Instrumentation and Technology Centre (AITC) is a leading technology innovator and instrument builder in Australia for both space and ground based telescopes. The centre is the technology wing of the Research School of Astronomy and Astrophysics at the Australian National University, and has over one hundred years of history in delivering forefront astronomical instrumentation for the national and international community, including NIFS and GSAOI for Gemini Observatory. We present a summary of the ground and space based instrumentation programs under development at the AITC as well as paradigm shifting technology developments underway together with industry and academia.

ERIS is an instrument that will both extend and enhance the fundamental diffraction limited imaging and spectroscopy capability for the VLT. It will replace two instruments that are now being maintained beyond their operational lifetimes, combine their functionality on a single focus, provide a new wavefront sensing module that makes use of the facility Adaptive Optics System, and considerably improve their performance. The instrument will be competitive with respect to JWST in several regimes, and has outstanding potential for studies of the Galactic Center, exoplanets, and high redshift galaxies. ERIS had its final design review in 2017, and is expected to be on sky in 2020. This contribution describes the instrument concept, outlines its expected performance, and highlights where it will most excel.

NIRSPEC is a 1-5 um echelle spectrograph in use on the Keck II Telescope since 1999. The spectrograph is capable of both moderate (R=λ/▵λ~2000) and high (R~25,000) resolution observations and has been a workhorse instrument across many astronomical fields, from planetary science to extragalactic observations. In the latter half of 2018, we will upgrade NIRSPEC to improve the sensitivity and stability of the instrument and increase its lifetime. The major components of the upgrade include replacing the spectrometer and slit-viewing camera detectors with Teledyne H2RG arrays and replacing all transputer-based electronics. We present detailed design, testing, and analysis of the upgraded instrument, including the finalized optomechanical design of the new 1-5 μm slit-viewing camera, detector characterization of the science and Engineering A grade arrays, electronics systems, and updated software design. The optomechanical design of the slit-viewing camera and replacement detector head assembly have both been assembled and cold-tested in our lab. We also show results from the GigE interface to the SAM/ASIC boards to control the H2RG. The upgrade will continue NIRSPEC’s legacy as a powerful near-infrared spectrograph behind one of the world’s most scientifically productive telescopes.

The LUCI instruments are a pair of NIR imagers and multi-object spectrographs located at the front bent Gregorian foci of the Large Binocular Telescope (LBT). One of their special features is their diffraction-limited imaging and long-slit spectroscopic capability in combination with the LBT adaptive secondary mirrors. This allows to achieve a spatial resolution down to 60mas and a spectral resolution of up to 25000. Switching from seeing-limited to diffraction-limited observations changes several operational aspects due to features such as the non-common path aberration or the flexure of the instruments. They all require novel techniques to optimize the image quality and to maximize the scientific return. Non-common path aberration can be corrected via look-up tables. For active flexure compensation the night-sky emission is used. The commissioning of the instruments in diffraction-limited mode on sky is largely finished and the instruments have been handed over to the LBT in April 2018.

The Arizona Lenslets for Exoplanet Spectroscopy (ALES) is the world’s first AO-fed thermal infrared integral field spectrograph, mounted inside the Large Binocular Telescope Interferometer (LBTI) on the LBT. An initial mode of ALES allows 3-4 μm spectra at R 20 with 0.026” spaxels over a 1”x1” field-of-view. We are in the process of upgrading ALES with additional wavelength ranges, spectral resolutions, and plate scales allowing a broad suite of science that takes advantage of ALES’s unique ability to work at wavelengths >2 microns, and at the diffraction limit of the LBT’s full 23.8 meter aperture.

By adding a dedicated coronagraph, ESO in collaboration with the Breakthrough Initiatives, modifies the Very Large Telescope mid-IR imager (VISIR) to further boost the high dynamic range imaging capability this instru- ment has. After the VISIR upgrade in 2012, where coronagraphic masks were first added to VISIR, it became evident that coronagraphy at a ground-based 8m-class telescope critically needs adaptive optics, even at wavelengths as long as 10μm. For VISIR, a work-horse observatory facility instrument in normal operations, this is ”easiest” achieved by bringing VISIR as a visiting instrument to the ESO-VLT-UT4 having an adaptive M2. This “visit” enables a meaningful search for Earth-like planets in the habitable zone around both α-Cen1,2. Meaningful here means, achieving a contrast of ≈ 10^-6 within ≈ 0.8arcsec from the star while maintaining basically the normal sensitivity of VISIR. This should allow to detect a planet twice the diameter of Earth. Key components will be a diffractive coronagraphic mask, the annular groove phase mask (AGPM), optimized for the most sensitive spectral band-pass in the N-band, complemented by a sophisticated apodizer at the level of the Lyot stop. For VISIR noise filtering based on fast chopping is required. A novel internal chopper system will be integrated into the cryostat. This chopper is based on the standard technique from early radio astronomy, conceived by the microwave pioneer Robert Dicke in 1946, which was instrumental for the discovery of the 3K radio background.

The CRIRES upgrade project (CRIRES+) will improve the performance and observing efficiency of the successful adaptive optics (AO) assisted CRIRES instrument. CRIRES was in operation from 2006 to 2014 at the 8m UT1 (Unit Telescope) of the Very Large Telescope (VLT, Cerro Paranal, Chile) observatory accessing a parameter space (wavelength range and spectral resolution) largely uncharted back then. CRIRES+ will be commissioned in summer 2018 at UT3 of the VLT. It will provide a spectral resolution of R=50.000 or 100.000 in an accessible wavelength range of 0.95 – 5.3 μm (YJHKLM bands). For each band there is a separate, performance optimized reflection grating as the cross dispersing element. The slit length of 10 arcsec will provide, in combination with the new focal plane array of three HAWAII 2RG detectors, cross-dispersed (7 – 9 orders simultaneous) echelle spectra. In total, the observing efficiency will be improved by a factor of 10 comparing CRIRES+ and CRIRES. Furthermore, the upgraded instrument will be equipped with a number of novel wavelength calibration units, including a gas absorption cell optimized for use in K band and an etalon system. A spectro-polarimetric unit will allow the recording of circular and linear polarized spectra. The new metrology system will ensure a very high system stability and repeatability. Last but not least the upgrade will be supported by dedicated data reduction software allowing the community to take full advantage of the new capabilities. The full system is being integrated at ESO and system testing has commenced. Acceptance of the instrument in Europe (PAE) is scheduled for the second quarter of 2018. Commissioning at the VLT observatory will start mid 2018. This article gives an overview of the final configuration of the instrument. The instrument will be available to the astronomic community from Spring 2019 with a call for proposals in October 2018.

SOXS (Son Of X-Shooter) will be a spectrograph for the ESO NTT telescope capable to cover the optical and NIR bands, based on the heritage of the X-Shooter at the ESO-VLT. SOXS will be built and run by an international consortium, carrying out rapid and longer term Target of Opportunity requests on a variety of astronomical objects. SOXS will observe all kind of transient and variable sources from different surveys. These will be a mixture of fast alerts (e.g. gamma-ray bursts, gravitational waves, neutrino events), mid-term alerts (e.g. supernovae, X-ray transients), fixed time events (e.g. close-by passage of minor bodies). While the focus is on transients and variables, still there is a wide range of other astrophysical targets and science topics that will benefit from SOXS. The design foresees a spectrograph with a Resolution-Slit product ≈ 4500, capable of simultaneously observing over the entire band the complete spectral range from the U- to the H-band. The limiting magnitude of R~20 (1 hr at S/N~10) is suited to study transients identified from on-going imaging surveys. Light imaging capabilities in the optical band (grizy) are also envisaged to allow for multi-band photometry of the faintest transients. This paper outlines the status of the project, now in Final Design Phase.

The OCTOCAM instrument concept was built on the principles of efficiency and simultaneity. The aim was not only optical throughput and excellent detector response, but also broad wavelength coverage, temporal resolution and a very good duty cycle to make the best possible use of every photon collected by a telescope. This instrument would be optimized for the study of transient astronomical sources. This lead to a multi-channel instrument with the capability of doing imaging and spectroscopy, which is currently being developed for the 8.1m Gemini South telescope. In the Gemini implementation, OCTOCAM will perform imaging of a 3'x3' field of view in 8 simultaneous channels (g, r, i, z, Y, J, H, Ks) or long slit (3') spectroscopy covering the range between 3700 and 23500 Angstrom at a resolution of ~4000. In this talk I will present the OCTOCAM instrument concept, the origin and development of the idea and the path to becoming a reality at an 8 m class telescope. I will cover the technical, management and personal lessons learned throughout a decade long path from the experience of the principal investigator of the project, which I was, from the beginning and until the end of 2017. Finally I will comment on the possible reinterpretations of OCTOCAM on smaller and larger telescopes.

Microwave Kinetic Inductance Detectors, or MKIDS, have the ability to simultaneous resolve the wavelength of individual photons and time tag photons with microsecond precision. This opens up a number of exciting new possibilities and efficiency gains for optical/IR astronomy. In this paper we describe a plan to take the MKID technology, which we have demonstrated on the Palomar, Lick, and Subaru Telescopes, out of the realm of private instruments usable only by experts. Our goal is to incorporate MKIDs into a facility-class instrument at the Keck 1 Telescope that can be used by a large part of the astronomical community. This new instrument, the Keck Radiometer Array using KID ENergy Sensors (KRAKENS), will be a 30 kpix integral field spectrograph (IFS) with a 42.5” x 45” field of view, extraordinarily wide wavelength coverage from 380-1350 nm, and a spectral resolution R=λ/▵λ > 20 at 400 nm. Future add on modules could enable polarimetry and higher spectral resolution. KRAKENS will be built using the same style MKID arrays, cryostat, and similar readout electronics to those used in the successful 10 kpix DARKNESS instrument at Palomar and 20 kpix MEC instrument at Subaru, significantly reducing the technical risk.

We present the current status of the SCORPIO project, the facility instrument for Gemini South designed to perform follow up studies of transients in the LSST era while carrying out with unique efficiency a great variety of astrophysical programs. SCORPIO operates in the wavelength range 385-2350 nanometers, observing simultaneously in the grizYJHK bands. It can be used both in imaging (seeing limited) and spectroscopic (long-slit) mode, and thanks to the use of frame-transfer CCDs it can monitor variable sources with milli-second time-resolution. The project has recently passed PDR and is on schedule to be commissioned at the time of the LSST first light.

The Tomo-e Gozen is a wide-field high-speed camera for the Kiso 1.0-m Schmidt telescope, with a field-of-view of 20.7-deg² covered by 84 chips of 2k x 1k CMOS image sensors with 19-μm pixels. It is capable to take consecutive images at 2-fps in full-frame read with an absolute time accuracy of 0.2 millisecond. The sensors are operated without mechanical coolers owing to a low dark current at room temperature. A low read noise of 2-e^- achieves higher sensitivity than that with a CCD sensor in short exposures. Big data of 30-TBytes per night produced in the 2-fps observations is processed in real-time to quickly detect transient events and issue alerts for follow-ups.

The Evryscope is a new type of array telescope which monitors the entire accessible sky in each exposure. One Evryscope has covered the Southern hemisphere from Chile since 2015, and we will soon deploy another Evryscope to cover the North from Mount Laguna Observatory in California. Each telescope, with 692 MPix covering an 8000-square-degree field of view, builds many-year-length, high-cadence light curves for every accessible object brighter than ~16th magnitude. An overlapping 4000-square-degree region between each system will give simultaneous multicolor observations with a 8,500km baseline. Every night, we add more than a billion object detections to our databases, enabling the detection of exoplanet transits, microlensing events, nearby extragalactic transients, gravitational wave electromagnetic counterparts, and a wide range of other short timescale events. The Evryscopes are designed to complement surveys such as TESS, providing multi-color context, longer-term observations and higher cadence across the sky. Although the Evryscope telescopes are small, they integrate for more than 6 hours on each part of the sky each night, enabling the system to form high-cadence counterparts to surveys such as LSST. All data, over 600Gb per night, is recorded for realtime analysis. Co-adding achieves depths of g>17 each hour across the entire accessible sky, and our on-site pipelines add all object detections to our databases in realtime. I will discuss the system design, including building the telescopes for fully-robotic operation, actuating our lens-camera interface at few-micron precisions to optimize our image quality, and the big-data analysis required to explore the petabyte-scale dataset we are collecting over the next few years. I will also present the first results from the Southern Evryscope.

HiPERCAM is a quintuple-beam imager that saw first light on the 4.2 m William Herschel Telescope (WHT) in October 2017 and on the 10.4 m Gran Telescopio Canarias (GTC) in February 2018. The instrument uses re- imaging optics and 4 dichroic beamsplitters to record ugriz (300–1000 nm) images simultaneously on its five CCD cameras. The detectors in HiPERCAM are frame-transfer devices cooled thermo-electrically to 90°C, thereby allowing both long-exposure, deep imaging of faint targets, as well as high-speed (over 1000 windowed frames per second) imaging of rapidly varying targets. In this paper, we report on the as-built design of HiPERCAM, its first-light performance on the GTC, and some of the planned future enhancements.

Zwicky Transient Facility is an integrated, multi-band astronomical survey system optimized for sensitivity, observing cadence, and efficiency. The key subsystem consists of a 600 megapixel CCD focal plane mounted in a flat-fielding vacuum cryostat, located at the prime focus of the 1.2-meter Samuel Oschin Telescope at Palomar Observatory. Supporting subsystems include a new 2.4-meter optical shutter assembly, a 1.35-meter diameter aspheric corrector plate, a cryostat stabilizing hexapod, a commercial robotic arm-based exchanger, three 440 millimeter width filters, four guide/focus CCDs, and dedicated optics compensating individual field curvature over each of sixteen 6k x 6k science CCDs.To optimize ZTF efficiency, all telescope and dome drives were upgraded for higher speed and acceleration, fast readout electronics were implemented, and a sophisticated robotic control system has been implemented. We present for the first time on-sky results from the recently completed ZTF including its realized optical image quality, CCD noise, and observing efficiency performance and discuss engineering challenges that have been overcome. Early scientific results from the ZTF survey are also included.

Time has come to implement a new way to study the stellar physics from the ground with long-term uninterrupted time series, multi-color photometry, flexibility during observing runs and all for less money. PAIX, Photometer AntarctIca eXtinction, gives new insight to cope with unresolved stellar enigma and stellar oscillation challenges and bears witness, for the first time, to a new technology of the polar instrumental robotization under extreme human and weather conditions in the heart of Antarctica. In fact, the stellar pulsation plays a crucial role in understanding the Universe, however progress is limited by the data accuracy needed to detect numerous modes of oscillations with small amplitudes and by the discontinuous nature of typical ground-based data strings which often introduce ambiguities in the determination of oscillation frequencies. The recent space missions enable to overcome both difficulties, However, the outcome of the space missions shows large gaps in terms of flexibility during the observing runs, the choice of targets, the repair of failures and the inexorable high costs. We present here the new technology from Antarctica, in particular from South Polar Site Dome C that benefits from great image quality and 150 days high time coverage, where the seeing reaches a median value of 1 arcsec during the polar night. We briefly describe the instrumental performances of PAIX, its low-cost commercial components, robotic telescope, multi-band photometer and automatic control, working under harsh weather conditions, even when the temperature reach values as low as -80°C. The polar mission PAIX challenges the space missions and even has more advantages than CoRoT and KEPLER in observing in UBVRI bands and then collecting multicolor light curves simultaneously of several targets. We discuss here the first outcomes of stellar physics from the heart of Antarctica during 10 polar nights and PAIX new results and perspectives on the pulsating stars from Antarctica, especially the connection between the stellar pulsation enigma and the Universe mysteries. Finally, we highlight the impact of PAIX -the robotic Antarctica photometer- on the Astronomy development.

In this paper, we present the preliminary optical system design of AST3-NIR camera, a wide-field infrared imager for 50cm Antarctic surveying telescope (AST3-3) to be deployed to Dome A, the Antarctic plateau. It is a joint project in which China is responsible for telescope hardware and control, logistics and deployment. Australia is responsible for instrument hardware design and control, and power generation. The camera uses two mosaic Leonardo detectors with 1280 x 1032 pixels each. The instrument is designed with a field of view(FOV) of 28.10 X 46.10 at the pixel scale of 1.35” per 15µm pixel. It is optimized for K dark band (2.26μm to 2.49 μm). The main challenges of this design are to produce a well-defined internal pupil stop located within cryogenic condition which reduces the thermal background and the correction of off-axis aberrations due to the large available field. Since the operating temperature of the camera could vary from -35°C to -90°C, the refocusing mechanism needs to be designed within the camera. The optical performance of the system will be demonstrated. We show the opto-mechanical error budget and compensation strategy that allows the built design to meet the optical performance.

The problem of atmospheric emission from OH molecules is a long standing problem for near-infrared astronomy. PRAXIS is a unique spectrograph which is fed by fibres that remove the OH background and is optimised specifically to benefit from OH-Suppression. The OH suppression is achieved with fibre Bragg gratings, which were tested successfully on the GNOSIS instrument. PRAXIS uses the same fibre Bragg gratings as GNOSIS in its first implementation, and will exploit new, cheaper and more efficient, multicore fibre Bragg gratings in the second implementation. The OH lines are suppressed by a factor of ∼ 1000, and the expected increase in the signal-to-noise in the interline regions compared to GNOSIS is a factor of ∼ 9 with the GNOSIS gratings and a factor of ∼ 17 with the new gratings. PRAXIS will enable the full exploitation of OH suppression for the first time, which was not achieved by GNOSIS (a retrofit to an existing instrument that was not OH-Suppression optimised) due to high thermal emission, low spectrograph transmission and detector noise. PRAXIS has extremely low thermal emission, through the cooling of all significantly emitting parts, including the fore-optics, the fibre Bragg gratings, a long length of fibre, and the fibre slit, and an optical design that minimises leaks of thermal emission from outside the spectrograph. PRAXIS has low detector noise through the use of a Hawaii-2RG detector, and a high throughput through a efficient VPH based spectrograph. PRAXIS will determine the absolute level of the interline continuum and enable observations of individual objects via an IFU. In this paper we give a status update and report on acceptance tests.

The Immersion GRating INfrared Spectrometer (IGRINS) was designed for high-throughput with the expectation of being a visitor instrument at progressively larger observing facilities. IGRINS achieves R∼45000 and > 20,000 resolution elements spanning the H and K bands (1.45-2.5μm) by employing a silicon immersion grating as the primary disperser and volume-phase holographic gratings as cross-dispersers. After commissioning on the 2.7 meter Harlan J. Smith Telescope at McDonald Observatory, the instrument had more than 350 scheduled nights in the first two years. With a fixed format echellogram and no cryogenic mechanisms, spectra produced by IGRINS at different facilities have nearly identical formats. The first host facility for IGRINS was Lowell Observatory’s 4.3-meter Discovery Channel Telescope (DCT). For the DCT a three-element fore-optic assembly was designed to be mounted in front of the cryostat window and convert the f/6.1 telescope beam to the f/8.8 beam required by the default IGRINS input optics. The larger collecting area and more reliable pointing and tracking of the DCT improved the faint limit of IGRINS, relative to the McDonald 2.7-meter, by ∼1 magnitude. The Gemini South 8.1-meter telescope was the second facility for IGRINS to visit. The focal ratio for Gemini is f/16, which required a swap of the four-element input optics assembly inside the IGRINS cryostat. At Gemini, observers have access to many southern-sky targets and an additional gain of ∼1.5 magnitudes compared to IGRINS at the DCT. Additional adjustments to IGRINS include instrument mounts for each facility, a glycol cooled electronics rack, and software modifications. Here we present instrument modifications, report on the success and challenges of being a visitor instrument, and highlight the science output of the instrument after four years and 699 nights on sky. The successful design and adaptation of IGRINS for various facilities make it a reliable forerunner for GMTNIRS, which we now anticipate commissioning on one of the 6.5 meter Magellan telescopes prior to the completion of the Giant Magellan Telescope.

Balloon-borne astronomy is a unique tool that allows for a level of image stability and significantly reduced atmospheric interference without the often prohibitive cost and long development time-scale that are characteristic of space-borne facility-class instruments. The Super-pressure Balloon-borne Imaging Telescope (SuperBIT) is a wide-field imager designed to provide 0.02" image stability over a 0.5 degree field-of-view for deep exposures within the visible-to-near-UV (300-900 um). As such, SuperBIT is a suitable platform for a wide range of balloon-borne observations, including solar and extrasolar planetary spectroscopy as well as resolved stellar populations and distant galaxies. We report on the overall payload design and instrumentation methodologies for SuperBIT as well as telescope and image stability results from two test flights. Prospects for the SuperBIT project are outlined with an emphasis on the development of a fully operational, three-month science flight from New Zealand in 2020.

Since its first light at the VLT in 2012, the Annular Groove Phase Mask (AGPM) has been used to implement vortex coronagraphy into AO-assisted infrared cameras at two additional world-leading observatories: the Keck Observatory and the LBT. In this paper, we review the status of these endeavors, and briefly highlight the main scientific results obtained so far. We explore the performance of the AGPM vortex coronagraph as a function of instrumental constraints, and identify the main limitations to the sensitivity to faint, off-axis companions in high-contrast imaging. These limitations include the AGPM itself, non-common path aberrations, as well as the data processing pipeline; we briefly describe our on-going efforts to further improve these various aspects. Based on the lessons learned from the first five years of on-sky exploitation of the AGPM, we are now preparing its implementation in a new generation of high-contrast imaging instruments. We detail the specificities of these instruments, and how they will enable the full potential of vortex coronagraphy to be unleashed in the future. In particular, we explain how the AGPM will be used to hunt for planets in the habitable zone of alpha Centauri A and B with a refurbished, AO-assisted version of the VISIR mid-infrared camera at the VLT (aka the NEAR project), and how this project paves the way towards mid-infrared coronagraphy on the ELT with the METIS instrument. We also discuss future LM-band applications of the AGPM with VLT/ERIS, ELT/METIS, and with a proposed upgrade of Keck/NIRC2, as well as future applications at shorter wavelengths, such as a possible upgrade of VLT/SPHERE with a K-band AGPM.

This paper reports on the installation and initial commissioning of LINC-NIRVANA (LN), an innovative high resolution, near-infrared imager for the Large Binocular Telescope (LBT). We present the delicate and difficult installation procedure, the culmination of a re-integration campaign that was in full swing at the last SPIE meeting. We also provide an update on the ongoing commissioning campaigns, including our recent achievement of First Light. Finally, we discuss lessons learned from the shipment and installation of a large complex instrument.

Direct Imaging of exoplanets is one of the most technically difficult techniques used to study exoplanets, but holds immense promise for not just detecting but characterizing planets around the nearest stars. Ambitious instruments at the world’s largest telescopes have been built to carry out this science: the Gemini Planet Imager (GPI), SPHERE at VLT, SCExAO at Subaru, and the P1640 and Stellar Double Coronagraph (SDC) at Palomar. These instruments share a common archetype consisting of an extreme AO system feeding a coronagraph for on-axis stellar light rejection followed by a focal plane Integral Field Spectrograph (IFS). They are currently limited by uncontrolled scattered and diffracted light which produces a coherent speckle halo in the image plane. A number of differential imaging schemes exist to mitigate these issues resulting in star-planet contrast ratios as deep as ~10^-6 at low angular separations. Surpassing this contrast limit requires high speed active speckle nullification from a focal plane wavefront sensor (FPWS) and new processing techniques. MEC, the Microwave Kinetic Inductance Detector (MKID) Exoplanet Camera, is a J-band IFS module behind Subaru Telescope’s SCExAO system. MEC is capable of producing an image cube several thousand times a second without the read noise that dominates conventional high speed IFUs. This enables it to integrate with SCExAO as an extremely fast FPWS while eliminating non-common path aberrations by doubling as a science camera. Key science objectives can be further explored if longer wavelengths (H and K band) are simultaneously sent to CHARIS for high resolution spectroscopy. MEC, to be commissioned at Subaru in early 2018, is the second MKID IFS for high contrast imaging following DARKNESS’ debut at Palomar in July 2016. MEC will follow up on young planets and debris disks discovered in the SEEDS survey or by Project 1640 as well as discover self-luminous massive planets. The increased sensitivity, combined with the advanced coronagraphs in SCExAO which have inner working angles (IWAs) as small as 0.03” at 1.2 μm, allows young Jupiter-sized objects to be imaged as close as 4 AU from their host star. If the wavefront control enabled by MEC is fully realized, it may begin to probe the reflected light of giant planets around some nearby stars, opening a new parameter space for direct imaging targeting older stars. While direct imaging of reflected light exoplanets is the most challenging of the scientific goals, it is a promising long-term path towards characterization of habitable planets around nearby stars using Extremely Large Telescopes (ELTs). With diameters of about 30-m, an ELT can resolve the habitable zones of nearby M-type stars, for which an Earth-sized planet would be at ~10^-7 contrast at 1 μm. This will complement future space-based high contrast optical imaging targeting the wider habitable zones of sun-like stars for ~10^-10 contrast earth analogs. We will present lessons learned from the first few months of MEC’s operation including initial lab and on-sky (weather permitting) results. We already have preliminary data from Palomar testing a new statistical speckle discrimination post-processing technique using the photon arrival time measured with MKIDs. Residual stellar light in the form of a speckle masquerading as a planetary companion is pulled from a modified Rician distribution and can be statistically discerned from a true off-axis Poisson point source. Additionally, the progress of active focal plane wavefront control will be briefly discussed.

The design and construction of CARMENES has been presented at previous SPIE conferences. It is a next-generation radial-velocity instrument at the 3.5m telescope of the Calar Alto Observatory, which was built by a consortium of eleven Spanish and German institutions. CARMENES consists of two separate échelle spectrographs covering the wavelength range from 0.52 to 1.71μm at a spec-tral resolution of R < 80,000, fed by fibers from the Cassegrain focus of the telescope. CARMENES saw “First Light” on Nov 9, 2015. During the commissioning and initial operation phases, we established basic performance data such as throughput and spectral resolution. We found that our hollow-cathode lamps are suitable for precise wavelength calibration, but their spectra contain a number of lines of neon or argon that are so bright that the lamps cannot be used in simultaneous exposures with stars. We have therefore adopted a calibration procedure that uses simultaneous star / Fabry Pérot etalon exposures in combination with a cross-calibration between the etalons and hollow-cathode lamps during daytime. With this strategy it has been possible to achieve 1-2 m/s precision in the visible and 5-10 m/s precision in the near-IR; further improvements are expected from ongoing work on temperature control, calibration procedures and data reduction. Comparing the RV precision achieved in different wavelength bands, we find a “sweet spot” between 0.7 and 0.8μm, where deep TiO bands provide rich RV information in mid-M dwarfs. This is in contrast to our pre-survey models, which predicted comparatively better performance in the near-IR around 1μm, and explains in part why our near-IR RVs do not reach the same precision level as those taken with the visible spectrograph. We are now conducting a large survey of 340 nearby M dwarfs (with an average distance of only 12pc), with the goal of finding terrestrial planets in their habitable zones. We have detected the signatures of several previously known or suspected planets and also discovered several new planets. We find that the radial velocity periodograms of many M dwarfs show several significant peaks. The development of robust methods to distinguish planet signatures from activity-induced radial velocity jitter is therefore among our priorities. Due to its large wavelength coverage, the CARMENES survey is generating a unique data set for studies of M star atmospheres, rotation, and activity. The spectra cover important diagnostic lines for activity (H alpha, Na I D1 and D2, and the Ca II infrared triplet), as well as FeH lines, from which the magnetic field can be inferred. Correlating the time series of these features with each other, and with wavelength-dependent radial velocities, provides excellent handles for the discrimination between planetary companions and stellar radial velocity jitter. These data are also generating new insight into the physical properties of M dwarf atmospheres, and the impact of activity and flares on the habitability of M star planets.

ESPRESSO is the next generation Euro- pean exoplanet hunter, combining the ef ciency of a modern echelle spectro- graph with extreme radial velocity and spectroscopic precision. ESPRESSO will be installed in the Combined Coudé Laboratory of the VLT and linked to the four Unit Telescopes (UT) through optical coudé trains, operated either with a single UT or with up to four UTs for 1.5 magnitude gain. The instrumental radial velocity precision will reach the 10 cm s–1 level and ESPRESSO will achieve a gain of two magnitudes with respect to its predecessor HARPS. This is the first VLT instrument using the incoherent combination of light from four telescopes and, together with the extreme precision requirements, calls for many innovative design solutions while ensuring the technical heritage of HARPS. The main scientific drivers for ESPRESSO are the search and characterisation of rocky exoplanets in the habitable zone of quiet, nearby G to M dwarf stars and the analysis of the variability of fundamental physical constants. As an ultra­stable high­resolution spectrograph however, ESPRESSO will allow new frontiers to be explored in most domains of astrophys­ics. The instrument has been installed at the Paranal Observatory in 2017 and will begin official operations by October 2018. High ­resolution spectroscopy has always been at the heart of astrophysics. It pro­vides the data that bring physical insight into the behaviour of stars, galaxies, interstellar and intergalactic media. Corre­spondingly, high-­resolution spectro­graphs have always been in high demand at major observatories, see, e.g., UVES at the VLT or HIRES at the Keck Tele­scope. As telescope apertures become larger, the capabilities of high-­resolution spectrographs extend to fainter and fainter objects. Besides this increase in photon-­collecting power, another aspect has emerged in recent years: the power of high-precision spectroscopy. In many applications there is the need for highly repeatable observations over long time­ scales where instrumental effects must be completely removed, or at least mini­mised. For instance, this is the case for radial velocity (RV) measurements, or, more generally, for the determination of the positions and shapes of spectral lines. In this respect, the HARPS spectrograph at the ESO 3.6-metre telescope (Mayor et al., 2003) has been a pioneering instru­ment. It has been widely recognised in the European astronomical community that a similar instrument on the VLT would be necessary. The need for a ground­based follow­up facility capable of high RV precision was stressed in the ESO–ESA working group report on extrasolar planets (Perryman et al., 2005). The research area “terrestrial planets in the habitable zone” is one of the main scientific topics for the next few decades in astronomy, and one of the main science drivers for the new gen­eration of extremely large telescopes (ELTs). For instance, the ESO–ESA working group report calls for “high-­precision radial-velocity instrumentation for the follow-­up of astro­metric and transit detections, to ensure the detection of a planet by a second in­dependent method, and to determine its true mass. For Jupiter­-mass planets, existing instrumentation may be techni­cally adequate, but observing time inade­quate; for Earth­-mass candidates, special-purpose instrumentation (like HARPS) on a large telescope would be required.” (Perryman et al., 2005, p. 63). The same concept is reiterated in the first recom­mendation: “Support experiments to im­ prove RV mass detection limits, e.g., based on experience from HARPS, down to those imposed by stellar surface phe­nomena” (Perryman et al., 2005, p. 72). Do the fundamental constants vary? This is one of the six big open questions in cosmology as listed in the ESA–ESO working group report for fundamental cosmology (Peacock et al., 2006). In the executive summary, the document states: “Quasar spectroscopy also offers the possibility of better constraints on any time variation of dimensionless atomic parameters such as the fine-structure constant α and the proton-­to-­electron mass ratio. Presently there exist controversial claims of evidence for variations in α, which potentially relate to the dynam­ics of dark energy. It is essential to vali­date these claims with a wider range of targets and atomic tracers.” This goal can only be reached with improved spec­troscopic capabilities. In this context the ESO Scientific Technical Committee (STC) recommended, at its 67th meeting in October 2007, the development of additional second gener­ation VLT instruments, and its detailed proposal was endorsed by the ESO Council at its 111th meeting in December 2007. Among the recommended instru­ments, a high-­resolution, ultra-­stable spectrograph for the VLT combined coudé focus arose as a cornerstone to com­plete the current second generation VLT instrument suite. In March 2007, following these recommendations, ESO issued a call for proposals, open to Member State institutes or consortia, to carry out the Phase A study for such an instrument. The submitted proposal was accepted by ESO and the ESPRESSO consortium was selected to carry out the project for the construction of this spectrograph. The main scientfiic drivers for this project were de ned by ESO as follows: 1. Measure high­-precision RV to search for rocky planets. 2. Measure the variation of physical con­stants. 3. Analyse the chemical composition of stars in nearby galaxies. The official project kick-off was held in February 2011. The design phase lasted about 2.5 years and ended with the final design review (FDR) in May 2013. The procurement of components and manu­facturing of subsystems lasted longer than planned due to manufacturing difficulties. Early 2015 the first subsystems were ready for integration in Europe, but Provisional Acceptance Europe of the instrument (the end integration and Verification) could only be held in June 2017. The transfer of the instrument to Paranal, installation took place in August-November 2017. The commission time cover the southern summer 2017-2018. Acceptance Paranal is planned to take place mid-2018. ESPRESSO is a fibre-fed, cross-dispersed, high-resolution, echelle spectrograph. The telescope light is fed to the instrument via a so-called ‘Coudé-Train’ optical system and within optical fibres. ESPRESSO is located in the Combined-Coudé Laboratory (incoherent focus) where a front-end unit can combine the light from up to 4 Unit Telescopes (UT) of the VLT. The target and sky light enter the instrument simultaneously through two separate fibres, which form together the ‘slit’ of the spectrograph. Several optical ‘tricks’ have been used to obtain high spectral resolution and efficiency despite the large size of the telescope and the 1 arcscec sky aperture of the instrument. At the spectrograph entrance the Anamorphic Pupil Slicing Unit (APSU) shapes the beam in order to compress it in cross-dispersion and splits in two smaller beams, while superimposing them on the echelle grating to minimize its size. The rectangular white pupil is then re-imaged and compressed. Given the wide spectral range, a dichroic beam splitter separates the beam in a blue and a red arm, which in turn allows to optimizing each arm for image quality and optical efficiency. The cross-disperser has the function of separating the dispersed spectrum in all its spectral orders. In addition, an anamorphism is re-introduced to make the pupil square and to compress the order height such that the inter-order space and the SNR per pixel are both maximized. Both functions are accomplished using Volume Phase Holographic Gratings (VPHGs) mounted on prisms. Finally, two optimised camera lens systems image the full spectrum from 380 nm to 780 nm on two large 92 mm x 92 mm CCDs with 10-um pixels.

Veloce is an ultra-stable fibre-fed R4 echelle spectrograph for the 3.9 m Anglo-Australian Telescope. The first channel to be commissioned, Veloce ‘Rosso’, utilises multiple low-cost design innovations to obtain Doppler velocities for sun-like and M-dwarf stars at <1 ms ^-1 precision. The spectrograph has an asymmetric white-pupil format with a 100-mm beam diameter, delivering R>75,000 spectra over a 580-930 nm range for the Rosso channel. Simultaneous calibration is provided by a single-mode pulsed laser frequency comb in tandem with a traditional arc lamp. A bundle of 19 object fibres ensures full sampling of stellar targets from the AAT site. Veloce is housed in dual environmental enclosures that maintain positive air pressure at a stability of ±0.3 mbar, with a thermal stability of ±0.01 K on the optical bench. We present a technical overview and early performance data from Australia's next major spectroscopic machine.

GIARPS (GIAno and haRPS) is a project devoted to have on the same focal station of the Telescopio Nazionale Galileo (TNG) both high resolution spectrographs, HARPS–N (VIS) and GIANO–B (NIR), working simultaneously. This could be considered the first and unique worldwide instrument providing cross-dispersed echelle spectroscopy at a resolution of 50,000 in the NIR range and 115,000 in the VIS and over in a wide spectral range (0.383−2.45 μm) in a single exposure. The science case is very broad, given the versatility of such an instrument and its large wavelength range. A number of outstanding science cases encompassing mainly extra-solar planet science starting from rocky planets search and hot Jupiters to atmosphere characterization can be considered. Furthermore both instruments can measure high precision radial velocities by means the simultaneous thorium technique (HARPS–N) and absorbing cell technique (GIANO–B) in a single exposure. Other science cases are also possible. GIARPS, as a brand new observing mode of the TNG started after the moving of GIANO–A (fiber fed spectrograph) from Nasmyth–A to Nasmyth–B where it was re–born as GIANO–B (no more fiber feed spectrograph). The official Commissioning finished on March 2017 and then it was offered to the community. Despite the work is not finished yet. In this paper we describe the preliminary scientific results obtained with GIANO–B and GIARPS observing mode with data taken during commissioning and first open time observations.

NIRPS (Near Infra Red Planet Searcher) is a new ultra-stable infrared ( YJH) fiber-fed spectrograph that will be installed on ESO’s 3.6-m telescope in La Silla, Chile. Aiming at achieving a precision of 1 m/s, NIRPS is designed to find rocky planets orbiting M dwarfs, and will operate together with HARPS (High Accuracy Radial velocity Planet Searcher). In this paper we describe NIRPS science cases, present its main technical characteristics and its development status.

The Infrared Doppler (IRD) instrument is a fiber-fed high-resolution NIR spectrometer for the Subaru telescope covering the Y,J,H-bands simultaneously with a maximum spectral resolution of 70,000. The main purpose of IRD is a search for Earth-mass planets around nearby M-dwarfs by precise radial velocity measurements, as well as a spectroscopic characterization of exoplanet atmospheres. We report the current status of the instrument, which is undergoing commissioning at the Subaru Telescope, and the first light observation successfully done in August 2017. The general description of the instrument will be given including spectrometer optics, fiber injection system, cryogenic system, scrambler, and laser frequency comb. A large strategic survey mainly focused on late-type M-dwarfs is planned to start from 2019.

PEPSI is the new fiber-fed and stabilized “Potsdam Echelle Polarimetric and Spectroscopic Instrument” for the Large Binocular Telescope (LBT). It covers the entire optical wavelength range from 384 to 913 nm in three exposures at resolutions of either R=λ/▵λ=50,000, 130,000 or 250,000. The R=130,000 mode can also be used with two dual-beam Stokes IQUV polarimeters. The 50,000-mode with its 12-pix sampling per resolution element is our “bad seeing” or “faint-object” mode. A robotic solar-disk-integration (SDI) telescope feeds solar light to PEPSI during day time and a 450-m fiber feed from the 1.8m VATT can be used when the LBT is busy otherwise. CCD characterization and a removal procedure for the spatial fixed-pattern noise were the main tasks left from the commissioning phase. Several SDI spectral time series with up to 300 individual spectra per day recovered the well-known solar 5-minute oscillation at a peak of 3 mHz (5.5min) with a disk-integrated radial-velocity amplitude of only 47 cm/s. Spectral atlases for 50 bright benchmark stars including the Sun were recently released to the scientific community, among them the ancient planet- system host Kepler-444. These data combine PEPSI’s high spectral resolution of R=250,000 with signal-to-noise ratio (S/N) of many hundreds to even thousands covering the entire optical to near-infrared wavelength range from 384 to 913 nm. Other early science cases were exoplanet transits including TRAPPIST-1, a spectrum of Boyajian's star that revealed strong and structured but stable ISM Na D lines, a spectrum of Oph allowing a redetermination of the ISM Li line doublet, and a first Doppler image of the young solar analog EK Dra that revealed starspots with solar-like penumbrae.

NEID is an ultra-stabilized, high-resolution, fiber-fed, spectrometer being built by a multi-institutional team for the 3.5 m WIYN telescope at Kitt Peak National Observatory, with a delivery date in 2019. The instrument is supported by the NN-EXPLORE program, a joint endeavor between NASA and the NSF to provide the exoplanet community with extreme ground-based Doppler radial velocity (RV) measurement capability. NEID's primary science objective is the discovery and characterization of terrestrial mass exoplanets, including follow-up of planets discovered by TESS and other spacecraft missions. Achieving these goals requires a multi-faceted approach that combines a state of the art Doppler instrument with a RV precision goal of 30 cm/s, a significantly improved understanding of the stellar radial velocity signal and intrinsic stellar variability, and large numbers of observations distributed optimally in time following guidelines refined over the past 25 years of RV exoplanet discovery. NEID uses a single-arm white pupil echelle optical design to produce R~100,000 spectra covering the complete wavelength range from 0.38 - 0.92 microns on a single 9k x 9k CCD. The optical bench and optics are stabilized with a state of the art temperature control system that achieves sub-mK stability, and are surrounded by a vacuum chamber that maintains 10^-7 Torr pressure or better. This extreme stability minimizes drift in the optics and optomechanical systems. Light is transfered from the telescope to the spectrometer using fiber-optic feeds that combine circular and octagonal fibers with a ball-lens double scrambler to provide high amounts of radial and azmuthal scrambling that minimize variations in the input illumination. These fibers interface with the WIYN telescope through a sophisticated new instrument port, which will provide atmospheric-dispersion correction and active tip-tilt to ensure precise and repeatable target positioning on the fiber. A three tiered calibration system utilizes a Laser Frequency Comb as the primary wavelength calibrator, while providing a stabilized etalon and ThAr and UNe Hollow-Cathode Lamps as high-reliability backup sources. An integrated exposure meter in the form of a low-resolution spectrometer measures precise chromatic exposure time centroids. A sophisticated data reduction pipeline that builds upon algorithms developed over decades of precision RV spectroscopy will automatically transform raw images and telemetry into RVs and other high-level data products, which will be served to users and the community through a NExScI portal. In this paper, we will provide an overview of the NEID project, including a progress update on the instrument integration and testing. We will also describe the WIYN operations plan, which is built around queue scheduled observations, and detail notional science programs that can be carried out with NEID, including the instrument team's GTO program. Finally, we will briefly discuss the impacts of stellar variability, which currently limit RV measurement precision well shy of the fundamental instrument limit, and which we and others are actively working to better understand and mitigate. Additional papers in this conference will describe the instrument subsystems in more detail.

The Habitable-Zone Planet Finder (HPF) is a stabilized, fiber-fed, NIR spectrometer recently commissioned at the 10m Hobby-Eberly telescope (HET). HPF has been designed and built from the ground up to be capable of discovering low mass planets around mid-late M dwarfs using the Doppler radial velocity technique. Novel apects of the instrument design include mili-kelvin temperature control, careful attending to fiber scrambling, and optics, mounting and detector readout schemes designed to minimize drifts and maximize the radial velocity precision. The optical design of the HPF is an asymmetric white pupil spectrograph layout in a vacuum cryostat cooled to 180 K. The spectrograph uses gold-coated mirrors, a mosaic echelle grating, and a single Teledyne Hawaii-2RG (H2RG) NIR detector with a 1.7-micron cutoff covering parts of the information-rich z, Y and J NIR bands at a spectral resolution of R~55,000. The use of 1.7 micron H2RG enables HPF to operate warmer than most other cryogenic instruments- with the instrument operating at 180K (allowing normal glasses to be used in the camera) and the detector at 120K. We summarize the engineering and commissioning tests on the telescope and the current radial velocity performance of HPF. With data in hand we revisit some of the design trades that went into the instrument design to explore the remaining tall poles in precision RV measurements in the near-infrared. HPF seeks to extend the precision radial velocity technique from the optical to the near-infrared, and in this presentation, we seek to share with the community our experience in this relatively new regime.

SPIRou is the new high resolution echelle spectropolarimeter and high-precision velocimeter, in the near infra- red, for the 3.6m Canada-France-Hawaii Telescope (CFHT Mauna Kea). This next generation instrument aims at detecting and characterizing Earth-like planets in the habitable zone of low-mass dwarfs and at investigating how magnetic fields impact star and planet formation. SPIRou consists of an achromatic polarimetric module coupled with a fluoride fiber link to a thermally-controlled cryogenic echelle spectrograph, and a Calibration Unit which can fed the light of hollow-cathod lamps, a radial velocity reference (Fabry-Pérot), or a cold source to the polarimeter and/or the spectrograph. Here we present a summary of the full performances obtained in laboratory tests carried in Toulouse (France), and the first results of the on-going commissioning at the CFHT. SPIRou covers a spectral range from 0.96 to 2.48 μm (YJHK domain) in one single exposure at a resolving power of 70 K, providing unpolarized and polarized spectra (with sensitivity 10 ppm) of stars, with a 10 15% peak throughput. Lab tests demonstrate that SPIRou is capable of achieving a relative radial velocity precision better than 0.2 m/s rms on timescales of 24 hr. Science operations of SPIRou are expected to start in 2018 S2, enabling significant synergies with major space and ground instruments such as the JWST, TESS, ALMA and later-on PLATO and the ELT.

MEGARA is the new generation IFU and MOS optical spectrograph built for the 10.4m Gran Telescopio CANARIAS (GTC). The project was developed by a consortium led by UCM (Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain) and UPM (Spain). The instrument arrived to GTC on March 28th 2017 and was successfully integrated and commissioned at the telescope from May to August 2017. During the on-sky commissioning we demonstrated that MEGARA is a powerful and robust instrument that provides on-sky intermediate-to-high spectral resolutions RFWHM ~ 6,000, 12,000 and 20,000 at an unprecedented efficiency for these resolving powers in both its IFU and MOS modes. The IFU covers 12.5 x 11.3 arcsec² while the MOS mode allows observing up to 92 objects in a region of 3.5 x 3.5 arcmin². In this paper we describe the instrument main subsystems, including the Folded-Cassegrain unit, the fiber link, the spectrograph, the cryostat, the detector and the control subsystems, and its performance numbers obtained during commissioning where the fulfillment of the instrument requirements is demonstrated.

On June 25th 2017, the new intermediate-resolution optical IFU and MOS of the 10.4-m GTC had its first light. As part of the tests carried out to verify the performance of the instrument in its two modes (IFU and MOS) and 18 spectral setups (identical number of VPHs with resolutions R=6000-20000 from 0.36 to 1 micron) a number of astronomical objects were observed. These observations show that MEGARA@GTC is called to fill a niche of high-throughput, intermediateresolution IFU and MOS observations of extremely-faint narrow-lined objects. Lyman-α absorbers, star-forming dwarfs or even weak absorptions in stellar spectra in our Galaxy or in the Local Group can now be explored to a new level. Thus, the versatility of MEGARA in terms of observing modes and spectral resolution and coverage will allow GTC to go beyond current observational limits in either depth or precision for all these objects. The results to be presented in this talk clearly demonstrate the potential of MEGARA in this regard.

We have recently commissioned a novel infrared (0:9-1:7 μm) integral field spectrograph (IFS) called the Wide Integral Field Infrared Spectrograph (WIFIS). WIFIS is a unique instrument that offers a very large field-of-view (5000 x 2000) on the 2.3-meter Bok telescope at Kitt Peak, USA for seeing-limited observations at moderate spectral resolving power. The measured spatial sampling scale is ~ 1 x 1" and its spectral resolving power is R ~ 2; 500 and 3; 000 in the zJ (0:9 - 1:35 μm) and Hshort (1:5 - 1:7 μm) modes, respectively. WIFIS's corresponding etendue is larger than existing near-infrared (NIR) IFSes, which are mostly designed to work with adaptive optics systems and therefore have very narrow fields. For this reason, this instrument is specifically suited for studying very extended objects in the near-infrared such as supernovae remnants, galactic star forming regions, and nearby galaxies, which are not easily accessible by other NIR IFSes. This enables scientific programs that were not originally possible, such as detailed surveys of a large number of nearby galaxies or a full accounting of nucleosynthetic yields of Milky Way supernova remnants. WIFIS is also designed to be easily adaptable to be used with larger telescopes. In this paper, we report on the overall performance characteristics of the instrument, which were measured during our commissioning runs in the second half of 2017. We present measurements of spectral resolving power, image quality, instrumental background, and overall efficiency and sensitivity of WIFIS and compare them with our design expectations. Finally, we present a few example observations that demonstrate WIFIS's full capability to carry out infrared imaging spectroscopy of extended objects, which is enabled by our custom data reduction pipeline.

The AAO’s TAIPAN instrument is a multi-object fibre positioner and spectrograph installed on the 1.2m UK-Schmidt telescope at Siding Spring Observatory. The positioner, a prototype for the MANIFEST positioner on the Giant Magellan Telescope, uses independently controlled Starbug robots to position a maximum of 300 optical fibres on a 32cm glass field plate (for a 6 degree field of view), to an accuracy of 5 microns (0.3 arcsec). The Starbug technology allows multi-object spectroscopy to be carried out with a minimum of overhead between observations, significantly decreasing field configuration time. Over the next 5 years the TAIPAN instrument will be used for two southern-hemisphere surveys: Taipan, a spectroscopic survey of 1x10^6 galaxies at z<0.3, and FunnelWeb, a stellar survey complete to Gaia G=12.5. In this paper we present an overview of the operational TAIPAN instrument: its design, construction and integration, and discuss the 2017 commissioning campaign and science verification results obtained in early 2018.

We present an update on the overall construction progress of the WEAVE next-generation spectroscopy facility for the William Herschel Telescope (WHT), now that all the major fabrication contracts are in place. We also present a summary of the current planning behind the 5-year initial phase of survey operations, and some detailed end-to-end science simulations that have been effected to evaluate the final on-sky performance after data processing. WEAVE will provide optical ground-based follow up of ground-based (LOFAR) and space-based (Gaia) surveys. WEAVE is a multi-object and multi-IFU facility utilizing a new 2-degree prime focus field of view at the WHT, with a buffered pick-and-place positioner system hosting 1000 multi-object (MOS) fibres, 20 integral field units, or a single large IFU for each observation. The fibres are fed to a single (dual-beam) spectrograph, with total of 16k spectral pixels, located within the WHT GHRIL enclosure on the telescope Nasmyth platform, supporting observations at R~5000 over the full 370-1000nm wavelength range in a single exposure, or a high resolution mode with limited coverage in each arm at R~20000. The project has experienced some delays in procurement and now has first light expected for the middle of 2019.

PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ~ 1.6-2.7Å. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The project recently started undertaking the commissioning process of a subsystem at the Subaru Telescope side, with the integration and test processes of the other subsystems ongoing in parallel. We are aiming to start engineering night-sky operations in 2019, and observations for scientific use in 2021. This article gives an overview of the instrument, current project status and future paths forward.

We present an overview and status update of the 4MOST project at the Final Design Review. 4MOST is a major new wide-field, high-multiplex spectroscopic survey facility under development for the VISTA telescope at the Paranal Observatory of ESO. Starting in 2022, 4MOST will deploy 2436 optical fibres in a 4.1 square degree field-of-view using a fibre positioner based on the tilting spine principle. The fibres will feed one high-resolution (R~20,000) and two low-resolution (R~5000) spectrographs that all have fixed configuration, 3-channel designs with identical 6k x 6k CCD detectors. Updated performance estimates will be presented based on components already manufactured and pre-production prototypes of critical subsystems. The 4MOST science goals are mostly driven by a number of large area, space-based observatories of prime European interest: Gaia and PLATO (Galactic Archeology and Stellar Physics), eROSITA (High-Energy Sky), and Euclid (Cosmology and Galaxy Evolution). Science cases based on these observatories, along with wide-area ground-based facilities such as LSST, VISTA and VST drive the ten Consortium Surveys covering a large fraction of the Southern sky, with bright time mostly devoted to the Milky Way disk and bulge areas and the Magellanic Clouds, and the dark/gray time largely devoted to extra-galactic targets. In addition there will be a significant fraction of the fibre-hours devoted to Community Surveys, making 4MOST a true general-purpose survey facility, capable of delivering spectra of samples of objects that are spread over a large fraction of the sky. The 4MOST Facility Simulator was created to show the feasibility of the innovative operations scheme of 4MOST with all surveys operating in parallel. The simulator uses the mock catalogues created by the science teams, simulates the spectral throughput and detection of the objects, assigns the fibres at each telescope pointing, creates pointing distributions across the sky and simulates a 5-year survey (including overhead, calibration and weather losses), and finally does data quality analyses and computes the science Figure-of-Merits to assess the quality of science produced. The simulations prove the full feasibility of running different surveys in parallel.

MIRADAS (Mid-resolution InfRAreD Astronomical Spectrograph) is the facility near-infrared multi-object echelle spectrograph for the Gran Telescopio Canarias (GTC) 10.4-meter telescope. MIRADAS operates at spectral resolution R=20,000 over the 1-2.5µm bandpass), and provides multiplexing (up to N=12 targets) and spectro-polarimetry. The MIRADAS consortium includes the University of Florida, Universidad de Barcelona, Universidad Complutense de Madrid, Instituto de Astrofísica de Canarias, Institut d'Estudis Espacials de Catalunya and Universidad Nacional Autonoma de Mexico, as well as partners at A-V-S (Spain), New England Optical Systems (USA), and IUCAA (India). MIRADAS completed its Final Design Review in 2015, and in this paper, we review the current status and overall system design for the instrument, with scheduled delivery in 2018. We particularly emphasize key developments in cryogenic robotic probe arms for multiplexing, a macro-slicer mini-IFU, an advanced cryogenic spectrograph optical system, and a SIDECAR-based array control system for the 1x2 HAWAII-2RG detector mosaic.

The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 square degrees will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. We present an overview of the instrumentation, the main technical requirements and challenges, and the current status of the project.

After completion of its final-design review last year, it is full steam ahead for the construction of the MOONS instrument - the next generation multi-object spectrograph for the VLT. This remarkable instrument will combine for the first time: the 8 m collecting power of the VLT, 1000 optical fibres with individual robotic positioners and both medium- and high-resolution spectral coverage acreoss the wavelength range 0.65μm - 1.8 μm. Such a facility will allow a veritable host of Galactic, Extragalactic and Cosmological questions to be addressed. In this paper we will report on the current status of the instrument, details of the early testing of key components and the major milestones towards its delivery to the telescope.

Based on the success of the SAMI integral field spectrograph (IFS) instrument on the Anglo-Australian Telescope (AAT) the capacity for large IFS nearby galaxy surveys on the AAT is being substantially expanded with a new instrument called Hector. The high filling-fraction imaging fibre bundles ‘hexabundles’ of the type used on SAMI, are being enlarged to cover up to 30-arcsec diameter. The aim is to reach two effective radii on most galaxies, where the galaxy rotation curve flattens and >75% of the specific angular momentum of disk galaxies is accounted for. Driven by the key science case, Hector will have a 1.3A spectral resolution, enabling high-order stellar kinematics to be measured on a larger fraction of galaxies than with any other IFS instrument. Hector will be on sky in 2019. The first module of Hector, Hector-I, will have 21 hexabundles and >42 sky fibres to observe 20 galaxies and a calibration star simultaneously. It consists of new blue and red-arm spectrographs that have been designed at the Australian Astronomical Observatory (AAO; now called AAO-Macquarie), coupled to the new hexabundles and robotic positioner from AAO-USydney (formerly the Sydney Astrophotonics Instrumentation Laboratory, SAIL) at Sydney University. A novel robotic positioning concept will compensate for varying telecentricity over the 2-degree-field of the AAT to recoup the 20% loss in light at the edge of the field. Hector-I will survey 15,000 galaxies. Additional modules in the future would result in 30,000 galaxies. Hector will take integral field spectroscopy on galaxies with z<0.15 in the 4MOST WAVES-North and WAVES-South∗ regions. The WAVES data, which will come later, will give the environment metrics neces- sary to relate how local and global environments influence galaxy growth through gas accretion, star formation and spins measured with Hector. The WALLABY ASKAP† survey will trace HI gas across the Hector fields, which in combination with Hector will give a complete view of gas accretion and star formation.

The LAMOST completed its first five years of operation in June 2017, and 9 million low resolution spectra are obtained. The spectrographs have been upgraded in 2017, and the resolution can reach up to 7500(with 2/3 slit). In the midresolution mode, the wavelength can cover 495nm-535nm(blue band) and 630nm-680nm(red band). The LAMOST will carry out the middle resolution spectroscopic survey in September 2018, and 3 million middle resolution spectra will be obtained. This paper describes the requirements, optical design and mechanical design of the LAMOST-MRS (the LAMOST middle resolution spectrograph)

The Gemini Infrared Multi-Object Spectrograph (GIRMOS) is a powerful new instrument being built to facility- class standards for the Gemini telescope. It takes advantage of the latest developments in adaptive optics and integral field spectrographs. GIRMOS will carry out simultaneous high-angular-resolution, spatially-resolved infrared (1 - 2.4 µm) spectroscopy of four objects within a two-arcminute field-of-regard by taking advantage of multi-object adaptive optics. This capability does not currently exist anywhere in the world and therefore offers significant scientific gains over a very broad range of topics in astronomical research. For example, current programs for high redshift galaxies are pushing the limits of what is possible with infrared spectroscopy at 8 -10- meter class facilities by requiring up to several nights of observing time per target. Therefore, the observation of multiple objects simultaneously with adaptive optics is absolutely necessary to make effective use of telescope time and obtain statistically significant samples for high redshift science. With an expected commissioning date of 2023, GIRMOS’s capabilities will also make it a key followup instrument for the James Webb Space Telescope when it is launched in 2021, as well as a true scientific and technical pathfinder for future Thirty Meter Telescope (TMT) multi-object spectroscopic instrumentation. In this paper, we will present an overview of this instrument’s capabilities and overall architecture. We also highlight how this instrument lays the ground work for a future TMT early-light instrument.

The Visible Integral-field Replicable Unit Spectrograph (VIRUS) consists of 156 identical spectrographs (arrayed as 78 pairs, each with a pair of spectrographs) fed by 35,000 fibers, each 1.5 arcsec diameter, at the focus of the upgraded 10 m Hobby-Eberly Telescope (HET). VIRUS has a fixed bandpass of 350-550 nm and resolving power R~750. The fibers are grouped into 78 integral field units, each with 448 fibers and 20 m average length. VIRUS is the first example of large-scale replication applied to optical astronomy and is capable of surveying large areas of sky, spectrally. The VIRUS concept offers significant savings of engineering effort and cost when compared to traditional instruments. The main motivator for VIRUS is to map the evolution of dark energy for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), using 0.8M Lyman-alpha emitting galaxies as tracers. The VIRUS array has been undergoing staged deployment starting in late 2015. Currently, more than half of the array has been populated and the HETDEX survey started in 2017 December. It will provide a powerful new facility instrument for the HET, well suited to the survey niche of the telescope, and will open up large spectroscopic surveys of the emission line universe for the first time. We will review the current state of production, lessons learned in sustaining volume production, characterization, deployment, and commissioning of this massive instrument.

The Maunakea Spectroscopic Explorer (MSE) is replacement of the existing 3.6-m Canada France Hawaii Telescope into a dedicated wide field highly multiplexed fiber fed spectroscopic facility. MSE is capable of observing over four thousand science targets simultaneously in two resolution modes. The paper describes the unique instrument system capabilities and its components starting from the telescope prime focus and ending at the spectrograph suite. The instrument system components have completed their conceptual designs and they include a Sphinx positioner system, fiber transmission system, low/moderate resolution and high resolution spectrographs and a calibration system. These components will be procured separately and the Project is responsible for their integration and the overall system performance afterward. The paper describes from a system perspective the specific design and interface constraints imposed on the components given the extra interface and integration considerations.

In this paper we present the Australian Astronomical Observatory’s concept design for Sphinx - a fiber positioner with 4,332 “spines” on a 7.77mm pitch for CFHT’s Mauna Kea Spectroscopic Explorer (MSE) Telescope. Based on the Echidna technology used with FMOS (on Subaru) and 4MOST (on VISTA), the next evolution of the tilting spine design delivers improved performance and superior allocation efficiency. Several prototypes have been constructed that demonstrate the suitability of the new design for MSE. Results of prototype testing are presented, along with an analysis of the impact of tilting spines on the overall survey efficiency. The Sphinx fiber positioner utilizes a novel metrology system for spine position feedback. The metrology design and the careful considerations required to achieve reliable, high accuracy measurements of all fibers in a realistic telescope environment are also presented.

Multi-object spectrometers (MOSs) are astronomical instruments capable of accurately acquiring spectra of up to several hundreds of objects of interest in a single exposure. Digital micromirror devices (DMDs) have proven to be an excellent candidate for use as slit masks in both terrestrial and space-based MOSs because they are highly reliable and rapidly re-configurable. The Rochester Institute of Technology Multi-Object Spectrometer (RITMOS) is a terrestrial DMD-based MOS, which uses a newer generation DMD, with improved scattered light characteristics. RITMOS utilizes a 0.700 XGA DMD with a micromirror pitch of 13.68 microns and a micromirror flip angle of 12 degrees. By design, RITMOS covers the spectral range 3900 - 4900 angstroms, with a dispersion of 0.7 angstroms per pixel; the resolving power is R∼5300. Performance evaluation has been conducted both in the laboratory and on-sky. The results presented here show that DMD-based MOSs are highly capable instruments, offering great observational flexibility, while achieving excellent signal-to-noise ratios by optimally rejecting the sky background.

We present the opto-mechanical design of SAMOS, the SOAR Adaptive-Module Optical Spectrograph. SAMOS is a multi-object, reconfigurable-slit spectrograph designed to fully exploit the Ground Layer Adaptive Optics (GLAO) laser guide system of SOAR, i.e. the SOAR Adaptive Module (SAM). While it is designed to maximize sensitivity, it can also efficiently operate in regular seeing limited conditions. It will operate in the optical spectrum, covering a bandpass of 400 - 950 nm, in two exposures, utilizing four grims: two to produce low resolution spectra, i.e. R » 3000, as well as two narrow bandpass, high resolution spectra at R » 10, 000. The instrument uses a large-format Digital Micromirror Device (DMD), a programmable array of miniature mirrors, as a programmable slit to steer light from the telescope focal plane into either a spectroscopic arm or an imaging arm. The DMD can be reconfigured in seconds, allowing a vast range of slit widths and lengths; each being a multiple of mirrors wide and long. In SAMOS this facilitates the collection of up to as many as 200 spectra simultaneously, allowing a multitude of slit configurations, which can be optimized for seeing and science, and, at the same time, enables parallel science imaging of non-dispersed targets through a suite of broad and narrowband filters. SAMOS is a very compact instrument, by necessity. It attaches to the SOAR Adaptive Optics Module (SAM), fitting in a location with limited space, requiring a highly folded, compact optical design. This paper discusses the opto-mechanical design of SAMOS, including the overall system design as well as detailed descriptions of the optical mounts and mechanisms.

In this paper we will report on the status of the instrumentation project for the European Southern Observatory's Extremely Large Telescope (ELT). Three instruments are in the construction phase: HARMONI, MICADO and METIS. The multi-conjugate adaptive optics system for MICADO, MAORY, is also under development. Preliminary Design Reviews of all of these systems are planned to be completed by mid-2019. The construction of a laser tomographic module for HARMONI is part of "Phase 2" of the ELT: the design has been advanced to Preliminary Design level in order to define the interface to the HARMONI spectrograph. Preparations for the next instruments have also been proceeding in parallel with the development of these instruments. Conceptual design studies for the multi-object spectrograph MOSAIC, and for the high resolution spectrograph HIRES have been completed and reviewed. We present the current design of each of these instruments and will summarise the work ongoing at ESO related to their development.

The GMT-Consortium Large Earth Finder (G-CLEF) is an instrument that is being designed to exceed the state-of-the-art radial velocity (RV) precision achievable with the current generation of stellar velocimeters. It is simultaneously being designed to enable a wide range of scientific programs, prominently by operating to blue wavelengths (< 3500Å). G-CLEF will be the first light facility instrument on the Giant Magellan Telescope (GMT) when the GMT is commissioned in 2023. G-CLEF is a fiber-fed, vacuum-enclosed spectrograph with an asymmetric white pupil echelle design. We discuss several innovative structural, optical and control system features that differentiate G-CLEF from previous precision RV instruments.

MICADO will enable the ELT to perform diffraction limited near-infrared observations at first light. The instrument’s capabilities focus on imaging (including astrometric and high contrast) as well as single object spectroscopy. This contribution looks at how requirements from the observing modes have driven the instrument design and functionality. Using examples from specific science cases, and making use of the data simulation tool, an outline is presented of what we can expect the instrument to achieve.

With the successful completion of our preliminary design phase, we will present an update on all design aspects of the IRIS near-infrared integral field spectrograph and wide-field imager for the Thirty Meter Telescope (TMT). IRIS works with the Narrow Field Infrared Adaptive Optics System (NFIRAOS) to make observations at the diffraction limit of TMT at wavelengths between 0.84 and 2.4 microns. The imager has been expanded to a 34 arcsec field of view and the spectrograph has a wide range of filter and spectral format combinations with a contiguous field of view up to 112x128 spatial elements. Among the many challenges the instrument faces, and has tried to address in its design, are atmospheric dispersion up to 100 times the sampling scale, unprecedented saturation issues in crowded fields, and the need for integrated on-instrument wavefront sensors. But the scientific payoff is enormous and IRIS on TMT will open entirely new opportunities in all areas of astrophysical science.

The Mid-Infrared ELT Imager and Spectrograph (METIS) is one of three first light instruments on the ELT. It will provide high-contrast imaging and medium resolution, slit-spectroscopy from 3 – 19um, as well as high resolution (R ~ 100,000) integral field spectroscopy from 2.9-5.3µm. All modes observe at the diffraction limit of the ELT, by means of adaptive optics, yielding angular resolutions of a few tens of milliarcseconds. The range of METIS science is broad, from Solar System objects to active galactic nuclei (AGN). We will present an update on the main science drivers for METIS: circum-stellar disks and exoplanets. The METIS project is now in full steam, approaching its preliminary design review (PDR) in 2018. In this paper we will present the current status of its optical, mechanical and thermal design as well as operational aspects. We will also discuss the challenges of building an instrument for the ELT, and the required technologies.

We report the design evolution for the GMT Integral Field Spectrograph, (GMTIFS). To support the range of operating modes – a spectroscopic channel providing integral field spectroscopy with variable spaxel scales, and a parallel imaging channel Nyquist sampling the LTAO corrected field of view - the design process has focused on risk mitigation for the demanding operational tolerances. We summarise results from prototype components, confirming concepts are meeting the necessary specifications. Ongoing review and simulation of the scientific requirements also leads to new demonstrations of the science that will be made possible with this new generation of high performance AO assisted instrumentation.

When combined with the huge collecting area of the ELT, MOSAIC will be the most effective and flexible Multi-Object Spectrograph (MOS) facility in the world, having both a high multiplex and a multi-Integral Field Unit (Multi-IFU) capability. It will be the fastest way to spectroscopically follow-up the faintest sources, probing the reionisation epoch, as well as evaluating the evolution of the dwarf mass function over most of the age of the Universe. MOSAIC will be world-leading in generating an inventory of both the dark matter (from realistic rotation curves with MOAO fed NIR IFUs) and the cool to warm-hot gas phases in z=3.5 galactic haloes (with visible wavelenth IFUs). Galactic archaeology and the first massive black holes are additional targets for which MOSAIC will also be revolutionary. MOAO and accurate sky subtraction with fibres have now been demonstrated on sky, removing all low Technical Readiness Level (TRL) items from the instrument. A prompt implementation of MOSAIC is feasible, and indeed could increase the robustness and reduce risk on the ELT, since it does not require diffraction limited adaptive optics performance. Science programmes and survey strategies are currently being investigated by the Consortium, which is also hoping to welcome a few new partners in the next two years.

We discuss the latest developments of a spectrograph for the Giant Magellan Telescope. The instrument is designed to provide high throughput, moderate resolution, optical spectra for the telescope and be capable of flexible and rapid reconfiguration. The focal plane can be populated with custom slit masks or multiple fibers, allowing for observations of multiple objects simultaneously.

We present the results from the phase A study of ELT-HIRES, an optical-infrared High Resolution Spectrograph for ELT, which has just been completed by a consortium of 30 institutes from 12 countries forming a team of about 200 scientists and engineers. The top science cases of ELT-HIRES will be the detection of life signatures from exoplanet atmospheres, tests on the stability of Nature’s fundamental couplings, the direct detection of the cosmic acceleration. However, the science requirements of these science cases enable many other groundbreaking science cases. The baseline design, which allows to fulfil the top science cases, consists in a modular fiber- fed cross-dispersed echelle spectrograph with two ultra-stable spectral arms providing a simultaneous spectral range of 0.4-1.8 μm at a spectral resolution of ~100,000. The fiber-feeding allows ELT-HIRES to have several, interchangeable observing modes including a SCAO module and a small diffraction-limited IFU.

The Arrayed Wide-Angle Camera System (AWACS) is an astronomical wide-field imaging system that utilizes hundreds of replicated small optical units spread across the focal surface of two-mirror telescopes. The AWACS concept is completely different from the traditional monolithic lens-based corrector design and can potentially enable a compact, cost-effective, and high-performance wide-field corrector system for the Extremely Large Telescopes. In this paper, we detail some of the AWACS design features and the results from early laboratory prototype tests.

The Wide Field Optical Spectrometer (WFOS) is a seeing limited, multi-object spectrograph and first light instrument for the Thirty Meter Telescope (TMT) scheduled for first observations in 2027. The spectrograph will deliver a minimum resolution of R~5,000 over a simultaneous wavelength range of 310 nm to 1,000 nm with a multiplexing goal of between 20 and 700 targets. The WFOS team consisting of partners in China, India, Japan, and the United States has completed a trade study of two competing concepts intended to meet the design requirements derived from the WFOS detailed science case. The first of these design concepts is a traditional slit mask instrument capable of delivering R~1,000 for up to 100 simultaneous targets using 1 x 7 arc second slits, and a novel focal plane slicing method for R~5,000 on up to 20 simultaneous targets can be achieved by reformatting the 1 arc-second wide slits into three 0.3 arc-second slits projected next to each other in the spatial direction. The second concept under consideration is a highly multiplexed fiber based system utilizing a robotic fiber positioning system at the focal plane containing 700 individual collectors, and a cluster of up to 12 replicated spectrographs with a minimum resolution of R~5,000 over the full pass band. Each collecting element will contain a bundle of 19 fibers coupled to micro-lens arrays that allow for contiguous coverage of targets and adaptation of the f/15 telescope beam to f/3.2 for feeding the fiber system. This report describes the baseline WFOS design, provides an overview of the two trade study concepts, and the process used to down-select between the two options. Also included is a risk assessment regarding the known technical challenges in the selected design concept.

TMT’s wide field optical spectrograph is a multi-object, first-light instrument with broad continuous wavelength coverage (0.310 – 1.0 m) at a moderate spectral resolution of R = 5000. The international WFOS design team has recently completed the downselect of two design approaches: a slicer-based monolithic architecture and a fiber-based modular concept. We present here the end-to-end conceptual design for the fiber-based optical spectrograph. Included are the front-end focal reduction optics for coupling light into the fibers, the spectrograph collimator and camera optics, and the dispersive architecture for each color channel. The highly multiplexed fiber-WFOS presents a unique design challenge in keeping costs for the modular spectrographs low while maintaining performance gains afforded by the TMT, and in particular the TMT plus ground-layer adaptive optics (GLAO). A full performance analysis including predicted spectral resolution and throughput is presented for the design.

We present the first results using a new SCHOTT 1% narrow band filter in the near infrared for the CIRCE camera of the 10.4m GTC telescope. The goal of the project is to detect very distant galaxies at the dawn of the Universe. These remote and extremely faint galaxies are selected by their Ly-alpha emission. For this project SCHOTT manufactured a high transmission 11 nm narrow band filter which has been used in the fully cryogenic near-infrared camera CIRCE of the Gran Telescopio Canarias Telescope. A steep interference filter Bandpass with FWHM 11nm centered at 1254nm was coated on a fused silica substrate. The filter achieved excellent maximum transmission and deep out of band blocking. This was achieved by using magnetron sputtering for the filter coating process. We report on the spectral and interferometric results of the filter and the scientific results achieved with a first set of observations.

The design and performance of a three-channel image and long-slit spectrograph for the new 4-m telescope in China are described. The direct imaging covers a 3 arcmin by 3 arcmin field of view and a large wavelength range 370-1,600 nm, it has two optical channels and one near infrared channel with different filters. The spectrograph with a long slit is to provide two observing modes including the following spectral resolutions: R1000 and R5000. For dispersing optical elements it use volume-phased holographic grisms (VPHG) at each of the spectroscopic modes to simplify the camera system. The low resolution mode (R1000) is provided by consecutive observations with the spectral ranges: 360-860 nm, however it adopts only one VPHG for the first light. The spectral range of medium resolution mode (R5000) is 460- 750nm, it is constrained with the use of a 4k × 4k CCD detector of 15 μm pixel size. Peak efficient in the spectrograph are achieved to be higher than 50% in different resolution mode.

Coupling a high-contrast imaging instrument to a high-resolution spectrograph has the potential to enable the most detailed characterization of exoplanet atmospheres, including spin measurements and Doppler mapping. The high-contrast imaging system serves as a spatial filter to separate the light from the star and the planet while the high-resolution spectrograph acts as a spectral filter, which differentiates between features in the stellar and planetary spectra. The Keck Planet Imager and Characterizer (KPIC) located downstream from the current W. M. Keck II adaptive optics (AO) system will contain a fiber injection unit (FIU) combining a high-contrast imaging system and a fiber feed to Keck’s high resolution infrared spectrograph NIRSPEC. Resolved thermal emission from known young giant exoplanets will be injected into a single-mode fiber linked to NIRSPEC, thereby allowing the spectral characterization of their atmospheres. Moreover, the resolution of NIRSPEC (R = 37,500 after upgrade) is high enough to enable spin measurements and Doppler imaging of atmospheric weather phenomenon. The module was integrated at Caltech and shipped to Hawaii at the beginning of 2018 and is currently undergoing characterization. Its transfer to Keck is planned in September and first on-sky tests sometime in December.

The Simultaneous-color Wide-field Infrared Multi-object Spectrograph, SWIMS, is a first-generation near-infrared instrument for the University of Tokyo Atacama Observatory (TAO) 6.5m Telescope now being constructed in northern Chile. To utilize the advantage of the site that almost continuous atmospheric window appears from 0.9 to 2.5 μm, the instrument is capable of simultaneous two-color imaging with a field-of-view of 9.′6 in diameter or λ/▵λ 1000 multi-object spectroscopy at 0.9–2.5 μm in a single exposure. The instrument has been trans- ported in 2017 to the Subaru Telescope as a PI-type instrument for carrying out commissioning observations before starting science operation on the 6.5m telescope. In this paper, we report the latest updates on the instrument and present preliminary results from the on-sky performance verification observations.

An overview of the optical design for the SOXS spectrograph is presented. SOXS (Son Of X-Shooter) is the new wideband, medium resolution (R>4500) spectrograph for the ESO 3.58m NTT telescope expected to start observations in 2021 at La Silla. The spectroscopic capabilities of SOXS are assured by two different arms. The UV-VIS (350-850 nm) arm is based on a novel concept that adopts the use of 4 ion-etched high efficiency transmission gratings. The NIR (800- 2000 nm) arm adopts the ‘4C’ design (Collimator Correction of Camera Chromatism) successfully applied in X-Shooter. Other optical sub-systems are the imaging Acquisition Camera, the Calibration Unit and a pre-slit Common Path. We describe the optical design of the five sub-systems and report their performance in terms of spectral format, throughput and optical quality. This work is part of a series of contributions^1-9 describing the SOXS design and properties as it is about to face the Final Design Review.

We present the NIR spectrograph of the Son Of XShooter (SOXS) instrument for the ESO-NTT telescope at La Silla (Chile). SOXS is a R~4,500 mean resolution spectrograph, with a simultaneously coverage from about 0.35 to 2.00 μm. It will be mounted at the Nasmyth focus of the NTT. The two UV-VIS-NIR wavelength ranges will be covered by two separated arms. The NIR spectrograph is a fully criogenic echelle-dispersed spectrograph, working in the range 0.80- 2.00 μm, equipped with an Hawaii H2RG IR array from Teledyne, working at 40 K. The spectrograph will be cooled down to about 150 K, to lower the thermal background, and equipped with a thermal filter to block any thermal radiation above 2.0 μm. In this poster we will show the main characteristics of the instrument along with the expected performances at the telescope.

We report on the upgraded One Degree Imager (ODI) at the WIYN 3.5 meter telescope at the Kitt Peak Observatory after the focal plane was expanded by an additional seventeen detectors in spring 2015. The now thirty Orthogonal Transfer Array CCD detectors provide a total field of view of 40’ x 48’ on the sky. The newly added detectors underwent a design revision to mitigate reduced charge transfer efficiency under low light conditions. We discuss the performance of the focal plane and challenges in the photometric calibration of the wide field of view, helped by the addition of telescope baffles. In a parallel project, we upgraded the instrument’s three filter arm mechanisms, where a degrading worm-gear mechanism was replaced by a chain drive that is operating faster and with high reliability. Three more filters, a u’ band and two narrow band filters were added to the instrument’s complement, with two additional narrow band filters currently in procurement (including an Hα filter). We review the lessons learned during nearly three years of operating the instrument in the observatory environment and discuss infrastructure upgrades that were driven by ODI’s needs.

SPRAT1 is a low resolution (R ∼ 300) long-slit spectrograph operating in the optical range 400 – 800 nm. It employs a linear layout with deployable optics and can image a 7.5 × 1.8 arcmin field during target acquisition. SPRAT has successfully operated on the robotic 2-metre Liverpool Telescope (LT)² on La Palma since late 2014, with >1000 calibration arc spectra and acquisition images taken since installation. Reliable autonomous acquisition without human intervention requires stricter stability criteria to reliably locate a target object in a long-slit spectrograph. We describe methods used to characterise the mechanical repeatability in deployment of the slit and optical components using calibration arcs and standard star spectra, together with acquisition field images. The effect of the instrument orientation and annual temperature variations on the accuracy in locating a target in the imaging plane is characterised together with longer term drifts. The characterisation is compared with the initial design goals of the instrument and used to calculate correction coefficients.

Time variation of the atmospheric water vapor is an important problem to achieve accurate photometry in ground-based mid-infrared observations. Long-term (~ minutes or hours) variation has been already known, but short-term (~ seconds) variation has not been quantified in previous studies. We evaluate this short-term variation and the photometric error in the mid-infrared observations at the TAO site by using actual astronomical data. Estimated photometric errors are typically less than 1% but show 2-5% in two of fifteen cases. This suggests that the short-term variation of the water vapor is one of the factors which limit the photometric accuracy in ground based mid-infrared observations.

The LSST Camera focal plane comprises twenty-one raft tower modules (RTMs), each with nine CCD sensors and their associated electronics. RTMs are assembled at Brookhaven National Lab and shipped to SLAC National Lab, where they must be re-verified before being assembled into the full focal plane. The process for accepting an RTM at SLAC has been thoroughly documented, including unpacking a raft from its shipping container, verifying aliveness of the electrical connections, performing metrology and electro-optical testing in an environment similar to the full Camera, and finally storing the RTM until it can be installed into the LSST Camera

In the era of Extremely Large Telescopes, the current generation of 8-10m facilities are likely to remain competitive at far-blue visible wavelengths for the foreseeable future. High-efficiency (<20%) observations of the ground UV (300- 400 nm) at medium resolving power (R~20,000) are required to address a number of exciting topics in stellar astrophysics, while also providing new insights in extragalactic science. Anticipating strong demand to better exploit this diagnostic-rich wavelength region, we revisit the science case and instrument requirements previously assembled for the CUBES concept for the Very Large Telescope.

The 4.1-m SOAR telescope needs fast tip-tilt guiding and active correction of focus and astigmatism to reach good image quality allowed by the excellent site seeing. A concept of the new guider with a 2×2 wavefront sensor is presented. It uses the X-Y positioning mechanism of the current guider, while the pick-off arm, camera, and detector are replaced by the new hardware. The pick-off arm has 2 positive lenses to collimate the beam, with an internal focus adjustment to compensate for focus offset in the science instrument and for the field curvature. The 4 spots are formed by a mirror with slightly tilted segments, located near the camera. The detector is an EM CCD; guiding on stars as faint as V=17 mag is possible using the correlation algorithm for centroiding; aberrations are measured on the averaged images. Results of the on-sky tests of the new guider prototype are presented.

In order to accommodate new instrumentation arriving in early 2018, the Canada-France-Hawaii Telescope (CFHT) converted one of its coudé spectrograph rooms into a cleanroom. The new instrumentation required ISO 8 conditions with a desired performance of ISO 7. The turn-key solutions available all provide much higher levels of performance at prices well outside the budget of the project, so we modified the room using a more cost effective in-house approach. We discuss the requirements of the new instrumentation, new administrative rules and procedures, changes made to the room and new equipment, and the resulting performance.

The Mid-Infrared Multi-field Imager for gaZing at the UnKnown Universe (MIMIZUKU) is a mid-infrared camera and spectrograph developed as a first-generation instrument on the University of Tokyo Atacama Observatory (TAO) 6.5-m telescope. MIMIZUKU covers a wide wavelength range from 2 to 38 μm and has a unique optical device called Field Stacker which realizes accurate calibration of variable atmospheric transmittance with a few percent accuracy. By utilizing these capabilities, MIMIZUKU realizes mid-infrared long-term monitoring, which has not been challenged well. MIMIZUKU has three optical channels, called NIR, MIR-S, and MIR-L, to realize the wide wavelength coverage. The MIR-S channel, which covers 6.8–26 μm, has been completed by now. We are planning to perform engineering observations with this channel at the Subaru telescope before the completion of the TAO 6.5-m telescope. In this paper, we report the results of the laboratory tests to evaluate the optical and detector performances of the MIR-S channel. As a result, we confirmed a pixel scale of 0.12 arcsec/pix and a vignetting- free field of view of 2./0 1./8. The instrument throughputs for imaging modes are measured to be 20–30%. Those for N - and Q -band spectroscopy modes are 17 and 5%, respectively. As for the detector performance, we derived the quantum efficiency to be 40–50% in the mid-infrared wavelength region and measured the readout noise to be 3000–6000 electrons, which are larger than the spec value. It was found that this large readout noise degrades the sensitivity of MIMIZUKU by a factor of two.

We present the commissioning of an IFU based on image-slicers and a 2D-Field-of-View Scanning System (FoV-SS) for the GREGOR Infrared Spectrograph (GRIS). The prototype of the image-slicer has eight slices of 1.8 mm x 0.1 mm in Zerodur, covering an area of 20 arcsec². The FoV-SS, equipped with three Degrees of Freedom (DoF), allows to scan a region of 1 arcmin², feeding the image-slicer with different portions of the field of view. A batch of tests was done during the Assembly, Integration and Verification (AIV) at GREGOR telescope.

SOXS will be a unique spectroscopic facility for the ESO NTT telescope able to cover the optical and NIR bands thanks to two different arms: the UV-VIS (350-850 nm), and the NIR (800-1800 nm). In this article, we describe the design of the visible camera cryostat and the architecture of the acquisition system. The UV-VIS detector system is based on a e2v CCD 44-82, a custom detector head coupled with the ESO continuous flow cryostats (CFC) cooling system and the NGC CCD controller developed by ESO. This paper outlines the status of the system and describes the design of the different parts that made up the UV-VIS arm and is accompanied by a series of contributions describing the SOXS design solutions (Ref. 1–12).

The South African Astronomical Observatory (SAAO) is currently developing WiNCam, the Wide-field Nasmyth Camera, to be mounted on Lesedi, the observatory’s new 1-metre telescope. This paper discusses the design and results for the remotely-operated camera system. The camera consists of an E2V-231-C6 Back Illuminated Scientific Charge Coupled Device (CCD) sensor with 6144x6160 pixels, four outputs operating in non-inverted mode. This is to date the largest single chip CCD-system developed at SAAO. The CCD is controlled with a modified Inter-University Centre for Astronomy and Astrophysics (IUCAA) Digital Sampler Array Controller (IDSAC) utilizing digital correlated double sampling. The camera system will have full-frame and frame-transfer read out modes available with sub-windowing and pre-binning abilities. Vacuum through-wall PCB technology is used to route signals through the vacuum interface between the controller and the CCD. A thin, compact, 125x125mm aperture, sliding-curtain-mechanism shutter was designed and manufactured together with a saddle-type filter-magazine-gripper system. The CCD is cryogenically cooled using a Stirling Cooler with active vibration cancellation; CCD temperature control is done with a Lake Shore Temperature Controller. A Varian Ion Pump and Activated Charcoal are used to maintain good vacuum and to prolong intervals between vacuum pump down. The various hardware components of the system are connected using distributed software architecture, and a web-based GUI allows remote and scripted operation of the instrument.

The Next Generation Palomar Spectrograph (NGPS) is designed for Cassergrain focus of the Hale 200-inch telescope to replace the old Palomar Double Spectrograph (DBSP). NGPS have higher throughput, efficiency and realities spectrograph. NGPS is designed as three channels to cover the wavelength from 365nm to 1050nm with no spectral gap and delivers a resolving power with a 1.5” slit exceeding R=1800 overall the observable range. The peak efficiency of the whole throughput (from sky to detector) at the wavelength is 35.3% which is consistent with throughput achieved by some of the world’s most efficient spectrographs.

SOXS (Son of X-Shooter) will be the new medium resolution (R~4500 for a 1 arcsec slit), high-efficiency, wide band spectrograph for the ESO-NTT telescope on La Silla. It will be able to cover simultaneously optical and NIR bands (350-2000nm) using two different arms and a pre-slit Common Path feeding system. SOXS will provide an unique facility to follow up any kind of transient event with the best possible response time in addition to high efficiency and availability. Furthermore, a Calibration Unit and an Acquisition Camera System with all the necessary relay optics will be connected to the Common Path sub-system. The Acquisition Camera, working in optical regime, will be primarily focused on target acquisition and secondary guiding, but will also provide an imaging mode for scientific photometry. In this work we give an overview of the Acquisition Camera System for SOXS with all the different functionalities. The optical and mechanical design of the system are also presented together with the preliminary performances in terms of optical quality, throughput, magnitude limits and photometric properties.

MIMIZUKU (Mid-infrared Multi-field Imager for gaZing at the UnKnown Universe) is a near- to mid-infrared camera for the 6.5-m TAO (The university of Tokyo Atacama Observatory) telescope. To realize both the compactness of the instrument and the wide field of view of 2 arcmin, MIMIZUKU has unique reflective optics, which is composed of off-axis aspherical mirrors made of machined aluminum. These mirrors should be placed and aligned very precisely with the accuracy of < 0.01 mm and < 0.01 degrees. We performed the experiments to test whether MIMIZUKU optics works as designed at cryogenic temperature. We present the evaluation of imaging performance and the distortion on the focal plane of MIMIZUKU.

Washburn Astronomical Laboratories of the University of Wisconsin-Madison Astronomy Department is developing a near infrared (NIR) integral field spectrograph for the 11-meter Southern African Large Telescope (SALT). This instrument will extend SALT’s capabilities into the NIR, providing medium resolution spectroscopy over the wavelength range of 0.8 to 1.7 microns. The integral field unit (IFU) is optimized for sampling nearby galaxies with an on-sky hexagonal extent of 24 x 28 arcsec containing 217 fibers of 1.33 arcsec diameter (median SALT seeing is 1.5 arcsec). Two separate blocks of 15 sky fibers are adjustable to distances ranging 54 to 165 arcsec from the IFU. This spectrograph, formerly known as RSS-NIR, was originally designed to mount at prime focus coupled to an optical spectrograph through a dichroic beam-splitter. The need to simplify telescope operations at prime focus prompted its reconfiguration into a fiber-fed, cooled, bench spectrograph, resulting in lower instrumental thermal background with a separate cooled collimator, stabilization of the pupil illumination in the spectrograph due to the azimuthal scrambling properties of fibers, and higher throughput at short wavelengths. Field-flattening and sky subtraction with the existing slit spectrograph has been challenging due to SALT’s varying pupil as the instrument payload tracks across the fixed primary mirror during observations. Simulations show that fiber scrambling of the pupil will improve the achievable sky subtraction residuals by 1-2 orders of magnitude. In this paper we present an overview of the reconfigured spectrograph design, its improved expected performance, and the new science drivers for NIR integral field spectroscopy.

Skylines and associated background is and will become a major issue for the near-infrared instrumentation for large telescopes. Due to telescopes size in the future, the temporal variation of the sky background can become a real issue using standard techniques of sky subtraction (cross-beam switching, dithering, etc.), if we want to reach a precision below 1%. Only the understanding of the temporal behavior of sky background (in a short period of time) can help us, to better correct the sky background and minimize the final residual. Using ESO archives of two infrared IFU instruments at the VLT (X-Shooter and KMOS). We have studied the behavior of the sky background in two skyline-free region at 1.1 and 1.8 microns, the selected region were inspected visually to avoid small skylines that can affect the measures (See Flores et al., 2016). This analyze complete the study realized by Yang et al. (2012) in the optical region using FORS2 data. Preliminary analysis shows that the sky continuum background at 1.1 and 1.8 microns, in regions of 0.6x0.6 and 0.6x1.2 sq arcsec has temporal variation of 0.6 to 3% for consecutive exposure time of 900s and 600s, respectively. we also found that the variations of the bottom of the sky at 1.8 microns are 2 times more important than the variations at 1.2 microns. This result will be included in future simulations using standard sky subtraction techniques, in particular to reevaluate the performances of instruments aiming to detect ultra faint objects/ features.

We present the data reduction pipeline, MEAD, for Arizona Lenslets for Exoplanet Spectroscopy (ALES), the first thermal infrared integral field spectrograph designed for high-contrast imaging. ALES is an upgrade of LMIRCam, the 1 - 5 μm imaging camera for the Large Binocular Telescope, capable of observing astronomical objects in the thermal infrared (3 - 5 μm) to produce simultaneous spatial and spectral data cubes. The pipeline is currently designed to perform L-band (2.8 - 4.2 μm) data cube reconstruction, relying on methods used extensively by current near-infrared integral field spectrographs. ALES data cube reconstruction on each spectra uses an optimal extraction method. The calibration unit comprises a thermal infrared source, a monochromator and an optical diffuser designed to inject specific wavelengths of light into LBTI to evenly illuminate the pupil plane and ALES lenslet array with monochromatic light. Not only does the calibration unit facilitate wavelength calibration for ALES and LBTI, but it also provides images of monochromatic point spread functions (PSFs). A linear combination of these monochromatic PSFs can be optimized to fit each spectrum in the least-square sense via x² fitting.

The World Space Observatory--Ultraviolet (WSO--UV) is a Russian-Spanish space mission born as a response to the growing up demand for UV facilities by the astronomical community. WSO-UV mission will make observations with spectrographs and imagers in UV domain (115-310 nm). For many astrophysical tasks of the mission Core program high resolution spectroscopic observations (R = 50000) will require ground support spectroscopic observations in spectral domain of 300-1000 nm. For these purposes we are upgrading existing facilities of Special Astrophysical Observatory, including NES, ESPRI and CAES spectrographs, and installing new ones. Nesmith Echellè Spectrograph (NES) of 6-m telescope with its fused silica optics allows to get spectra with R=70000 in 310-800 nm spectral region. We estimate its instrumental polarization on the 3-th flat mirror. Echellè Spectrograph of PRImary focus (ESPRI) for faint object spectrapolarimetry with R=25000 is under construction now. The 1-m telescope will be equipped by Cassegrain echellè spectrograph CAES. Here we present detail information on such instrumentation and our recent achievements. This paper provides an information on instrumentation update.

We report on the upgrade of the fiber link of FIES, the high-resolution echelle spectrograph at the Nordic Optical Telescope (NOT). In order to improve the radial velocity (RV) stability of FIES, we replaced the circular fibers by octagonal and rectangular ones to utilize their superior scrambling performance. Two additional fibers for a planned polarimetry mode were added during the upgrade. The injection optics and the telescope front-end were also replaced. The first on-sky RV measurements indicate that the influence of guiding errors is greatly suppressed, and the overall RV precision of FIES has significantly improved.

The installation of fully-depleted Hamamatsu CCDs in GMOS-N in February/March 2017 marked the conclusion of the CCD upgrade project for the two Gemini Multi-Object Spectrographs. The corresponding upgrade for GMOS-S was completed in June/July 2014, so that both GMOS instruments are now operated with a detector array of three fully-depleted Hamamatsu CCDs. We present results from the commissioning of the GMOS-N Hamamatsu CCDs and discuss their on-sky performance. We provide a comparison of the GMOS-N and GMOSS detector parameters and summarize the main observing and data reduction strategies that apply to both detector arrays.

Characterization of an instrument’s detector is an essential part of assessing the overall performance and ca- pabilities of an instrument. We present our efforts to characterize the HAWAII-2RG detector on the imager component of the OSIRIS instrument at W. M. Keck Observatory. In particular, we will report the detector’s read noise, dark current, linearity, and persistence. We find a gain of 2.16 ± 0.34, in good agreement with Teledyne’s reported gain of 2.15. The maximum read noise of the detector is 23.4 ± 1.3 e^- decreasing with an increasing number of reads. We find an upper limit on the dark current of the detector to be < 0.021 e^-/pix/s. The detector is also linear to the 1% level up to 44,500 e^- and to the 5% level at 80,000 e^-. The maximum well depth is measured to be 119,000 e^-.

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a heavily modified Boeing 747SP aircraft, accommodating a 2.7 meter infrared telescope. This airborne observation platform operates at flight altitudes of up to 13.7 km (45,000 ft) and therefore allows a nearly unobstructed view of the visible and infrared universe at wavelengths between 0.3 µm and 1600 µm. The Focal Plane Imager (FPI+) is SOFIA’s main tracking camera. It uses a commercial, off-the-shelf camera with a thermoelectrically cooled EM-CCD. The back-illuminated sensor has a peak quantum efficiency greater than 95% at 550 nm and the dark current is as low as 0.01 e-/pix/sec. Since 2015, the FPI+ has been available to the community as a Facility Science Instrument, and can be used to observe stellar occultations by solar system objects such as dwarf planets, moons, asteroids, and comets, and transits of extra-solar planets. To date, SOFIA has conducted multi-channel observations of occultations, e.g. the occultation by Pluto in June of 2015 or the occultation by Triton in October 2017, using three instruments, HIPO and FLITECAM at the main instrument flange of the telescope, and the FPI+. This multi-wavelength sampling is important for enabling discrimination of particle sizes and constituents of hazes in the atmosphere of bodies such as Pluto and Triton, and the coma material of comets. Multi-wavelength observations also serve to allow us to place constraints on the chemical compositions of these formations. After the retirement of the two other instruments, the FPI+ is now SOFIA’s only remaining observing tool for occultations. In order to preserve some of the multi-color observing capability of the platform, we here discuss the addition of a second spectral channel to the FPI+. In a first upgrade step, a beamsplitter will split the incoming light and send it to two EMCCD cameras, one working in the ”blue”, e.g. SLOAN g’ band, and the other working in the ”red”, e.g. SLOAN i’ or z’ band. In a second upgrade step, the ”red” channel could be equipped with a NIR camera in order to provide a wider wavelength separation of the two bands. This will however require a modified dichroic coating on the tertiary (Nasmyth) mirror of the SOFIA telescope. This paper presents a preliminary design study of the opto-mechanical configuration of the dual channel FPI+.

LUCI1 and LUCI2 are a pair multi-mode, fully cryogenic near-infrared instruments installed at the Large Binoc- ular Telescope (LBT). The instruments provide imaging, long-slit and multi-object spectroscopy over a 4/ FoV in seeing-limited mode. Ground-layer AO (GLAO) correction for imaging and spectroscopy over the 4/ FoV is available using the ARGOS laser system, as well as diffraction-limited AO over a 30// FoV using the LBT first light AO (FLAO) system with natural guide stars. Internal flexure of the instrument is taken care of by passive and active flexure compensation. Image shifts in seeing-limited modes are compensated by a passive flexure con- trol algorithm using pre-defined look-up tables. For AO observations, passive compensation is replaced by active control. In the following, we present the details of the newly developed active flexure compensation algorithm for the LUCI instruments. We also describe some hardware modifications to the instruments and the results obtained with active flexure compensation.

A thermal-infrared polarimetric capability of the Infrared Camera and Spectrograph (IRCS) for the Subaru Telescope is described. A new half-wave retarder for the thermal-infrared band in 2–5 µm is introduced into the Waveplate Unit of the Nasmyth platform on the infrared side of the telescope to realize imaging- and low resolution spectro-polarimetry in that wavelength region. Through day-time calibrations using a wire-grid polarizer, the peak efficiency of the polarization is found to be 90-98% consistently in both imaging- and spectro- polarimetry in the thermal-infrared bands. In 2016 May and 2017 June, two engineering observing runs have been carried out to verify the on-sky performance.

The Son Of X-Shooter (SOXS)1 is a medium resolution spectrograph (R ~ 4500) proposed for the ESO 3.6m NTT. We present the optical design of the UV-VIS arm of SOXS which employs high efficiency ion-etched gratings used in first order (m = 1) as the main dispersers. The spectral band is split into four channels which are directed to individual gratings, and imaged simultaneously by a single three-element catadioptric camera. The expected throughput of our design is > 60% including contingency. The SOXS collaboration expects first light in early 2021. This paper is one of several papers presented in these proceedings_2-10 describing the full SOXS instrument.

We present the design and measured performance of the Aperture Wheel and the Pupil and Filter Wheel mechanisms for the NIX camera of the VLT/ERIS instrument. Both mechanisms were developed for high opto-mechanical precision and stability while operating at 70 K. We summarise the design constraints and considerations. Further, we have developed a dedicated cryo-test facility to allow measuring the position repeatability under nominal operational conditions. We demonstrate that the wheel mechanisms perform as designed and provide the measurement methodology and results of the opto-mechanical tolerances.

SOXS (Son of X-shooter) is a wide band, medium resolution spectrograph for the ESO NTT with a first light expected in early 2021. The instrument will be composed by five semi-independent subsystems: a pre-slit Common Path (CP), an Acquisition Camera (AC), a Calibration Unit (CU), the NIR spectrograph, and the UV-VIS spectrograph. In this paper, we present the mechanical design of the subsystems, the kinematic mounts developed to simplify the final integration procedure and the maintenance. The concept of the CP and NIR optomechanical mounts developed for a simple pre- alignment procedure and for the thermal compensation of reflective and refractive elements will be shown.

The GeMS/GSAOI pair has been in regular science operation since 2013 at the Gemini South telescope and regularly delivers close to diffraction limited imaging in the NIR bands over a wide field of view of 85" square. Although the original GeMS/GSAOI science cases intentionally did not specify any astrometric performance, the Gemini users community expressed a large interest into using it with this purpose. Both instruments are subject to gravity-induced flexures. GSAOI is often dismounted from the telescope in instrument exchanges, making a regular on-sky calibration strategy time prohibitive. In 2017, we installed a new GeMS calibration focal plane mask offering ~1600 pinhole sources with a position accuracy of ±25 μm equivalent to ±0.4 mas, which can be used to deliver distortion calibration. We evaluate the flexure effect in the GeMS/GSAOI pair and discuss how to facilitate the mask to calibrate intra-night distortion drifts.

We report design of acousto-optic imaging spectrometer for spectral and polarimetric photometry and commis- sioning of the instrument at 0.6-m F/12.5 telescope at the Southern Astronomical Station of Lomonosov Moscow State University. The spectrometer was operating over the spectral range 3800–5800 Å with the passband of 10 Å at the wavelength of 5000 Å The imaging spectrometer could be used for observations of objects with the minimum brightness of 12.5 mag (for 0.6-m telescope, 120 s exposition, and SNR∼10). Spatial resolution of the spectrometer was estimated better than 1.2”, and the field of view was ∼250”.

High-resolution infrared spectropolarimetry has many science applications in astrophysics. One of them is measuring weak magnetic fields using the Zeeman effect. Infrared domain is particularly advantageous as Zeeman splitting of spectral lines is proportional to the square of the wavelength while the intrinsic width of the line cores increases only linearly. Important science cases include detection and monitoring of global magnetic fields on solar-type stars, study of the magnetic field evolution from stellar formation to the final stages of the stellar life with massive stellar winds, and the dynamo mechanism operation across the boundary between fully- and partially-convective stars. CRIRES+ (the CRIRES upgrade project) includes a novel spectropolarimetric unit (SPU) based on polar- ization gratings. The novel design allows to perform beam-splitting very early in the optical path, directly after the tertiary mirror of the telescope (the ESO Very Large Telescope, VLT), minimizing instrumental polariza- tion. The new SPU performs polarization beam-splitting in the near-infrared while keeping the telescope beam mostly unchanged in the optical domain, making it compatible with the adaptive optics system of the CRIRES+ instrument. The SPU consists of four beam-splitters optimized for measuring circular and linear polarization of spectral lines in YJ and HK bands. The SPU can perform beam switching allowing to correct for throughput in each beam and for variations in detector pixel sensitivity. Other new features of CRIRES+, such as substantially increased wavelength coverage, stability and advanced data reduction pipeline will further enhance the sensitivity of the polarimetric mode. The combination of the SPU, CRIRES+ and the VLT is a unique facility for making major progress in understanding stellar activity. In this article we present the design of the SPU, laboratory measurements of individual components and of the whole unit as well as the performance prediction for the operation at the VLT.

Atmospheric composition provides essential markers of the most fundamental properties of giant exoplanets, such as their formation mechanism or internal structure. New-generation exoplanet imagers, like VLT/SPHERE or Gemini/GPI, have been designed to achieve very high contrast (< 15 mag) at small angular separations (<0.500) for the detection of young giant planets in the near-infrared, but they only provide very low spectral resolutions (R < 100) for their characterization. High-dispersion spectroscopy at resolutions up to 105 is one of the most promising pathways for the detailed characterization of exoplanets, but it is currently out of reach for most directly imaged exoplanets because current high-dispersion spectrographs in the near-infrared lack coronagraphs to attenuate the stellar signal and the spatial resolution necessary to resolve the planet. Project HiRISE (High-Resolution Imaging and Spectroscopy of Exoplanets) ambitions to develop a demonstrator that will combine the capabilities of two flagship instruments installed on the ESO Very Large Telescope, the high-contrast exoplanet imager SPHERE and the high-resolution spectrograph CRIRES+, with the goal of answering fundamental questions on the formation, composition and evolution of young planets. In this work, we will present the project, the first set of realistic simulations and the preliminary design of the fiber injection unit that will be implemented in SPHERE.

The Cherenkov Telescope Array (CTA) foresees, in its southern site (Chile), the implementation of up to 70 small-sized telescopes (SSTs), which will extend the energy coverage up to hundreds of TeV. It has been proposed that one of the first set of CTA SSTs will be represented by the ASTRI mini-array, which includes (at least) nine ASTRI telescopes. The endto-end prototype of such telescopes, named the ASTRI SST-2M, is installed in Italy and it is now completing the overall commissioning and entering the science verification phase. ASTRI telescopes are characterized by an optical system based on a dual-mirror Schwarzschild-Couder design and a camera at the focal plane composed of silicon photomultiplier sensors managed by a fast read-out electronics specifically designed. Based on a custom peak-detector mode, the ASTRI camera electronics is designed to perform Cherenkov signal detection, trigger generation, digital conversion of the signals and data transmission to the camera server. In this contribution we will describe the main features of the ASTRI camera, its performance and results obtained during the commissioning phase of the ASTRI SST-2M prototype in view of the ASTRI mini-array implementation.

CRIRES+ is the new high-resolution NIR echelle spectrograph intended to be operated at the platform B of VLT Unit telescope UT3. It will cover from Y to M bands (0.95-5.3um) with a spectral resolution of R = 50000 or R=100000. The main scientific goals are the search of super-Earths in the habitable zone of low-mass stars, the characterisation of transiting planets atmosphere and the study of the origin and evolution of stellar magnetic fields. Based on the heritage of the old adaptive optics (AO) assisted VLT instrument CRIRES, the new spectrograph will present improved optical layout, a new detector system and a new calibration unit providing optimal performances in terms of simultaneous wavelength coverage and radial velocity accuracy (a few m/s). The total observing efficiency will be enhanced by a factor of 10 with respect to CRIRES. An innovative spectro-polarimetry mode will be also offered and a new metrology system will ensure very high system stability and repeatability. Fiinally, the CRIRES+ project will also provide the community with a new data reduction software (DRS) package. CRIRES+ is currently at the initial phase of its Preliminary Acceptance in Europe (PAE) and it will be commissioned early in 2019 at VLT. This work outlines the main results obtained during the initial phase of the full system test at ESO HQ Garching.

We describe TCal, a mobile spectrophotometric calibration system that will be used to characterize the throughput as a function of wavelength of imaging systems at observatories around the world. TCal measurements will enhance the science return from follow-up observations of imaging surveys such as LSST (Large Synoptic Survey Telescope) and DES (Dark Energy Survey) by placing all tested imaging systems on a common photometric baseline. TCal uses a 1 nm bandpass tunable light source to measure the instrumental response function of imaging systems from 300 nm to 1100 nm, including the telescope, optics, filters, windows, and the detector. The system is comprised of a monochromator-based light source illuminating a dome flat field screen monitored by calibrated photodiodes, which allows determination of the telescope throughput as a function of wavelength. This calibration will be performed at 1-8m telescopes that expect to devote time towards survey follow-up. Performing the calibration on these telescopes will reduce systematic errors due to small differences in bandpass, making follow-up efforts more precise and accurate.

Washburn Astronomical Laboratories in the University of Wisconsin-Madison Astronomy Department is developing a near infrared (NIR) integral field spectrograph for the 11-meter Southern African Large Telescope (SALT). This instrument will extend SALT’s capabilities into the NIR, providing medium resolution spectroscopy over the wavelength range of 0.8 to 1.7 microns. Formerly known as RSS-NIR, this spectrograph was originally designed to mount at the prime focus of SALT and share a common collimator and spaceframe structure with the visible wavelength Robert Stobie Spectrograph (RSS-VIS). However, to maximize performance of both the instrument and telescope, its configuration has been changed into a fiber fed instrument located in the spectrometer room below the telescope7. This change necessitated the addition of several new components, including a separate collimator; a fiber integral field unit (IFU); a means to inject light from the telescope into the fibers; and a cooled enclosure to house the spectrograph, collimator, and pseudo-slit end of the fiber cable. The new collimator consists of four refractive elements, one of which is calcium fluoride, and requires a new lens barrel and support structure. The new fiber system incorporates a hexagonally arranged 217-fiber IFU and two mini-bundles containing 15 sky fibers each. The IFU is fabricated out of a two-part clam-shell stainless steel ferrule. The existing SALT fiber instrument feed (FIF) mechanism is adapted to position the IFU and sky bundles on sky, while a slave motion on flexure pivots ensures that the fibers remain telecentric. A 42-m protected fiber cable spans the distance between the telescope prime focus and the pseudo-slit in the spectrometer room. The cable is constructed out of four 25mm outer diameter flexible conduits. Within the conduit, each fiber is individually protected in its own Teflon tube. The route of the fiber cable through the telescope requires careful accommodation of controlled bending. The pseudo-slit comprises a line of mini v-groove blocks attached to the slit plate. The slit, collimator, and spectrograph are housed inside a 40 cold enclosure in the SALT spectrometer room. The cooling system, developed by Norlake Scientific to our specifications, carefully controls against thermal shock and humidity. This paper describes the design, integration, and laboratory verification of the reconfigured spectrograph system, as well as our experiences operating in a -40 ambient pressure environment.

Son Of X-Shooter (SOXS) is the new instrument for the ESO 3.5 m New Technology Telescope (NTT) in La Silla site (Chile) devised for the spectroscopic follow-up of transient sources. SOXS is composed by two medium resolution spectrographs able to cover the 350-2000 nm interval. An Acquisition Camera will provide a light imaging capability in the visible band. We present the procedure foreseen for the Assembly, Integration and Test activities (AIT) of SOXS that will be carried out at sub-systems level at various consortium partner premises and at system level both in Europe and Chile.

NIHTS is a first-generation instrument now in use on Lowell Observatory’s Discovery Channel Telescope. It is a nearinfrared prism spectrograph of the BASS design featuring high throughput and low dispersion that is intended for observations of faint solar system and astrophysical objects over the YJHK spectral range. An unusual feature is its ability to observe simultaneously with the Large Monolithic Imager, an optical CCD camera, by means of a dichroic fold mirror. This is particularly valuable for time-variable targets such as Kuiper Belt Objects, asteroids, exoplanet transits, and brown dwarfs. We describe its design details and performance both in the lab and on the telescope.