SOXS (Son Of X-Shooter) is a medium resolution (~4500) wide-band (0.35 - 2.0 μm) spectrograph which passed the Final Design Review in 2018. The instrument is planned to be installed at the NTT in La Silla and it is mainly composed by five different optomechanical subsystems (Common Path, NIR spectrograph, UV-VIS spectrograph, Camera, and Calibration) and other mechanical subsystems (Interface flange, Platform, cable corotator, and cooling). It is currently in the procurement and integration phase. In this paper we present the post-FDR modifications in the mechanical design due to the various iterations with the manufacturers and the actual procurement status. The last part describes the strategy used to keep under control the mechanical interfaces between the subsystems.
SOXS (Son Of X-Shooter) is the new medium resolution wide-band spectrograph to be installed at the 3.6m New Technology Telescope (NTT) in La Silla. SOXS will offer simultaneous wavelength coverage from 0.35 to 2.0 μm and will be dedicated to the study of transient and variable sources. While nominal optical performances of the system were presented in previous proceedings (Zanmar Sanchez et al. 2018), we here present a set of further analyses aimed to identify and quantify optical effects, due to changes in temperature and orientation of the instrument during alignment and operations.
SOXS will be the new spectroscopic facility for the ESO NTT telescope able to cover the optical and NIR bands by using two different arms: the UV-VIS (350-850 nm), and the NIR (800-2000 nm). In this article, we describe the development status of the visible camera cryostat, the architecture of the acquisition system and the progress in the electronic design. The UV-VIS detector system is based on a CCD detector 44-82 from e2v, a custom detector head, coupled with the ESO continuous flow cryostats (CFC), a custom cooling system, based on a Programmable Logic Controller (PLC), and the New General Controller (NGC) developed by ESO. This paper outlines the development status of the system, describes the design of the different parts that make up the UV- VIS arm and is accompanied by a series of information describing the SOXS design solutions in the mechanics and in the electronics parts. The first tests of the detector system with the UV-VIS camera will be shown.
The Son-Of-X-shooter (SOXS) is a dual arm spectrograph (UV-VIS and NIR) and Acquisition Camera (AC) due to mounted on the European Southern Observatory (ESO) 3.6m New Technology Telescope (NTT) in La Silla. Designed to simultaneously cover the optical and NIR wavelength range from 350-2050 nm, the instrument will be dedicated to the study of transient and variable events with many Target of Opportunity requests expected. The goal of the SOXS Data Reduction pipeline is to use calibration data to remove all instrument signatures from the SOXS scientific data frames for each of the supported instrument modes, convert this data into physical units and deliver them with their associated error bars to the ESO Science Archive Facility (SAF) as Phase 3 compliant science data products, all within 30 minutes. The primary reduced product will be a detrended, wavelength and flux calibrated, telluric corrected 1D spectrum with UV-VIS + NIR arms stitched together. The pipeline will also generate Quality Control (QC) metrics to monitor telescope, instrument and detector health. The pipeline is written in Python 3 and has been built with an agile development philosophy that includes adaptive planning and evolutionary development. The pipeline is to be used by the SOXS consortium and the general user community that may want to perform tailored processing of SOXS data. Test driven development has been used throughout the build using ‘extreme’ mock data. We aim for the pipeline to be easy to install and extensively and clearly documented.
SOXS is a new spectrograph for the New Technology Telescope (NTT), optimized for transient and variable objects, covering a wide wavelength range from 350 to 2000 nm. SOXS is equipped with a calibration unit that will be used to remove the instrument signatures and to provide wavelength calibration to the data. The
calibration unit will employ seven calibration lamps: a quartz-tungsten-halogen and a deuterium lamp for the that will be used to remove the instrument signatures and to provide wavelength calibration to the data. The calibration unit will employ seven calibration lamps: a quartz-tungsten-halogen and a deuterium lamp for the flat-field correction, a ThAr lamp and four pencil-style rare-gas lamps for the wavelength calibration. The light from the calibration lamps is injected into the spectrograph mimicking the f/11 input beam of the NTT, by using an integrating sphere and a custom doublet. The oversized illumination patch covers the length of the spectrograph slit homogeneously, with < 1% variation. The optics also supports the second mode of the unit, the star-simulator mode that emulates a point source by utilizing a pinhole mask. Switching between the direct illumination and pinhole modes is performed by a linear stage. A safety interlock switches off the main power when the lamp box cover is removed, preventing accidental UV exposure to the service personnel. All power supplies and control modules are located in an electronic rack at a distance from the telescope platform. In this presentation we describe the optical, mechanical, and electrical designs of the SOXS calibration unit, and report the status of development in which the unit is currently in the test and verification stage.
Son Of X-Shooter (SOXS) is a double-armed (UV-VIS, NIR) spectrograph designed to be mounted at the ESO-NTT in La Silla, now in its Assembly Integration and Verification (AIV) phase. The instrument is designed following a modular approach so that each sub-system can be integrated in parallel before their assembly at system level. INAF-Osservatorio Astronomico di Padova will deliver the Common Path (CP) sub-system, which represents the backbone of the entire instrument. In this paper, we describe the foreseen operation for the CP alignment and we report some results already achieved, showing that we envisaged the suitable setup and the strategy to meet the opto-mechanical requirements.
We present here the development status of the NIR spectrograph of the Son Of X-Shooter (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 cryogenic echelle-dispersed spectrograph, working in the range 0.80-2.00 μm, equipped with a Hawaii H2RG IR array from Teledyne. The whole spectrograph will be cooled down to about 150 K (but the array at 40 K), to lower the thermal background, and equipped with a thermal filter to block any thermal radiation above 2.0 μm. In this work, we will show the advanced phase of integration of the NIR spectrograph.
We present our progress on the UV-VIS arm of Son Of X-Shooter (SOXS), a new spectrograph for the NTT. Our design splits the spectral band into four sub-bands that are imaged onto a single detector. Each band uses an optimized high efficiency grating that operates in 1st order (m=1). In our previous paper we presented the concept and preliminary design. SOXS passed a Final Design Review in July 2018 and is well into the construction phase. Here we present the final design, performances of key manufactured elements, and the progress in the assembly. Based on the as-built elements, the expected throughput of the visual arm will be < 55%. This paper is accompanied by a series of contributions describing the progress made on the SOXS instrument.
SOXS (Son Of X-Shooter) will be the new medium resolution (R∼4500 for 100 slit), high-efficiency, wide band spectrograph for the ESO NTT at La Silla, optimized for classification and follow-up of transient events. SOXS will simultaneously cover UV-optical and NIR bands (0.35-2.00 micron) using two different arms and a pre-slit Common Path feeding system. The instrument will be also equipped by a Calibration Unit and an Acquisition Camera (AC) System. In this paper we present the final opto-mechanical design for the AC System and we describe its development status. The project is currently in manufacturing and integration phases.
We present the development of the End-to-End simulator for the SOXS instrument at the ESO-NTT 3.5-m telescope. SOXS will be a spectroscopic facility, made by two arms high efficiency spectrographs, able to cover the spectral range 350-2000 nm with resolving power R≈4500. The E2E model allows to simulate the propagation of photons starting from the scientific target of interest up to the detectors. The outputs of the simulator are synthetic frames, which will be mainly exploited for optimizing the pipeline development and possibly assisting for proper alignment and integration phases in laboratory and at the telescope. In this paper, we will detail the architecture of the simulator and the computational model, which are strongly characterized by modularity and flexibility. Synthetic spectral formats, related to different seeing and observing conditions, and calibration frames to be ingested by the pipeline are also presented.
The forthcoming SOXS (Son Of X-Shooter) will be a new spectroscopic facility for the ESO New Technology Telescope in La Silla, focused on transient events and able to cover both the UV-VIS and NIR bands. The instrument passed the Final Design Review in 2018 and is currently in manufacturing and integration phase. This paper is focused on the assembly and testing of the instrument control electronics, which will manage all the motorized functions, alarms, sensors, and electric interlocks. The electronics is hosted in two main control cabinets, divided in several subracks that are assembled to ensure easy accessibility and transportability, to simplify test, integration and maintenance. Both racks are equipped with independent power supply distribution and have their own integrated cooling systems. This paper shows the assembly strategy, reports on the development status and describes the tests performed to verify the system before the integration into the whole instrument.
Son of X-Shooter (SOXS) will be a high-efficiency spectrograph with a mean Resolution-Slit product of ~4500 over the entire band capable of simultaneously observing the complete spectral range 350-2000 nm. It consists of three scientific arms (the UV-VIS Spectrograph, the NIR Spectrograph, and the Acquisition Camera) connected by the Common Path system to the NTT, and the Calibration Unit. The Common Path is the backbone of the instrument and the interface to the NTT Nasmyth focus flange. The instrument project went through the Final Design Review in 2018 and is currently in Assembly Integration and test (AIT) Phase. This paper outlines the observing modes of SOXS and the efficiency of each subsystem and the laboratory test plan to evaluate it.
SOXS (Son Of X-Shooter) is a single object spectrograph, characterized by offering a wide simultaneous spectral coverage from U- to H-band, built by an international consortium for the 3.6-m ESO New Technology Telescope at the La Silla Observatory, in the Southern part of the Chilean Atacama Desert. The consortium is focussed on a clear scientific goal: the spectrograph will observe all kind of transient and variable sources discovered by different surveys with a highly flexible schedule, updated daily, based on the Target of Opportunity concept. It will provide a key spectroscopic partner to any kind of imaging survey, becoming one of the premier transient follow-up instruments in the Southern hemisphere. SOXS will study a mixture of transients encompassing all distance scales and branches of astronomy, including fast alerts (such as gamma-ray bursts and gravitational waves), mid-term alerts (such as supernovae and X-ray transients), and fixed-time events (such as the close-by passage of a minor planet or exoplanets). It will also have the scope to observe active galactic nuclei and blazars, tidal disruption events, fast radio bursts, and more. Besides of the consortium programs on guaranteed time, the instrument is offered to the ESO community for any kind of astrophysical target. The project has passed the Final Design Review and is currently in manufacturing and integration phase. This paper describes the development status of the project.
SOXS (Son Of X-Shooter) is a forthcoming instrument for ESO-NTT, mainly dedicated to the spectroscopic study of transient events and is currently starting the AIT (Assembly, Integration, and Test) phase. It foresees a visible spectrograph, a near-Infrared (NIR) spectrograph, and an acquisition camera for light imaging and secondary guiding. The optimal setup and the monitoring of SOXS are carried out with a set of software-controlled motorized components and sensors. The instrument control software (INS) also manages the observation and calibration procedures, as well as maintenance and self-test operations. The architecture of INS, based on the latest release of the VLT Software (VLT2019), has been frozen; the code development is in an advanced state for what concerns supported components and observation procedures, which run in simulation. In this proceeding we present the INS current status, focusing in particular on the ongoing efforts in the support of two non-standard, “special” devices. The first special device is the piezoelectric slit exchanger for the NIR spectrograph; the second special device is the piezoelectric tip-tilt corrector used for active compensation of mechanical flexures of the instrument. For both, which are commanded via a serial line, specific driver and simulators have been implemented.
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.
Son of X-Shooter (SOXS) will be a high-efficiency spectrograph with a mean Resolution-Slit product of 4500 (goal 5000) over the entire band capable of simultaneously observing the complete spectral range 350-2000 nm. It consists of three scientific arms (the UV-VIS Spectrograph, the NIR Spectrograph and the Acquisition Camera) connected by the Common Path system to the NTT and the Calibration Unit. The Common Path is the backbone of the instrument and the interface to the NTT Nasmyth focus flange. The light coming from the focus of the telescope is split by the common path optics into the two different optical paths in order to feed the two spectrographs and the acquisition camera. The instrument project went through the Preliminary Design Review in 2017 and is currently in Final Design Phase (with FDR in July 2018). This paper outlines the status of the Common Path system and is accompanied by a series of contributions describing the SOXS design and properties after the instrument Preliminary Design Review.
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.
SOXS (Son Of X-Shooter) is a unique spectroscopic facility that will operate at the ESO New Technology Telescope (NTT) in La Silla from 2021 onward. The spectrograph will be able to cover simultaneously the UV-VIS and NIR bands exploiting two different arms and a Common Path feeding system. We present the design of the SOXS instrument control electronics. The electronics controls all the movements, alarms, cabinet temperatures, and electric interlocks of the instrument. We describe the main design concept. We decided to follow the ESO electronic design guidelines to minimize project time and risks and to simplify system maintenance. The design envisages Commercial Off-The-Shelf (COTS) industrial components (e.g. Beckhoff PLC and EtherCAT fieldbus modules) to obtain a modular design and to increase the overall reliability and maintainability. Preassembled industrial motorized stages are adopted allowing for high precision assembly standards and a high reliability. The electronics is kept off-board whenever possible to reduce thermal issues and instrument weight and to increase the accessibility for maintenance purpose. The instrument project went through the Preliminary Design Review in 2017 and is currently in Final Design Phase (with FDR in July 2018). This paper outlines the status of the work and is part of a series of contributions describing the SOXS design and properties after the instrument Preliminary Design Review.
SOXS (Son Of X-Shooter) is a new spectrograph for the ESO NTT telescope, currently in the final design phase. The main instrument goal is to allow the characterization of transient sources based on alerts. It will cover from near-infrared to visible bands with a spectral resolution of R ∼ 4500 using two separate, wavelength-optimized spectrographs. A visible camera, primarily intended for target acquisition and secondary guiding, will also provide a scientific “light” imaging mode. In this paper we present the current status of the design of the SOXS instrument control software, which is in charge of controlling all instrument functions and detectors, coordinating the execution of exposures, and implementing all observation, calibration and maintenance procedures. Given the extensive experience of the SOXS consortium in the development of instruments for the VLT, we decided to base the design of the Control System on the same standards, both for hardware and software control. We illustrate the control network, the instrument functions and detectors to be controlled, the overall design of SOXS Instrument Software (INS) and its main components. Then, we provide details about the control software for the most SOXS-specific features: control of the COTS-based imaging camera, the flexures compensation system and secondary guiding.
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).
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.
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.
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 contributions1-9 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.
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 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 proceedings2-10 describing the full SOXS instrument.
SOXS (Son Of X-Shooter) will be a unique spectroscopic facility for the ESO-NTT 3.5-m telescope in La Silla (Chile), able to cover the optical/NIR band (350-1750 nm). The design foresees a high-efficiency spectrograph with a resolutionslit product of ~4,500, capable of simultaneously observing the complete spectral range 350 - 1750 nm with a good sensitivity, with light imaging capabilities in the visible band. This paper outlines the status of the project.
During 2013, a new visible camera has been finally installed and tested at the 60cm, robotic REM
telescope in the la Silla Observatory. REM is an Italian, fast-reacting telescope initially designed and built for the
immediate response to GRB automatic alerts, but since the first light in 2003 its usage has been covering a wider
range of astronomical interests. While the IR camera REMIR was reaching the expected limiting magnitudes, the
original ROSS visible camera suffered, since the beginning, of a rather poor performance. We set therefore to
implement a newer optical camera, leading to the design, tests and integration of ROS2, a dichroic-based four
channels imaging camera. The four Sloan-like pass bands are imaged, at the same time, in four quadrants of the
CCD, an Andor multilevel Peltier detector. The tests during the science commissioning show an impressive
improvement in the limiting magnitudes, reaching two magnitudes fainter than ROSS. Here we show the concept,
the tests and the user level product we are now offering at REM.
LINC-NIRVANA (LN) is the near-infrared, Fizeau-type imaging interferometer for the large binocular telescope (LBT) on Mt. Graham, Arizona (elevation of 3267 m). The instrument is currently being built by a consortium of German and Italian institutes under the leadership of the Max Planck Institute for Astronomy in Heidelberg, Germany. It will combine the radiation from both 8.4 m primary mirrors of LBT in such a way that the sensitivity of a 11.9 m telescope and the spatial resolution of a 22.8 m telescope will be obtained within a 10.5×10.5 arcsec 2 scientific field of view. Interferometric fringes of the combined beams are tracked in an oval field with diameters of 1 and 1.5 arcmin. In addition, both incoming beams are individually corrected by LN’s multiconjugate adaptive optics system to reduce atmospheric image distortion over a circular field of up to 6 arcmin in diameter. A comprehensive technical overview of the instrument is presented, comprising the detailed design of LN’s four major systems for interferometric imaging and fringe tracking, both in the near infrared range of 1 to 2.4 μm, as well as atmospheric turbulence correction at two altitudes, both in the visible range of 0.6 to 0.9 μm. The resulting performance capabilities and a short outlook of some of the major science goals will be presented. In addition, the roadmap for the related assembly, integration, and verification process are discussed. To avoid late interface-related risks, strategies for early hardware as well as software interactions with the telescope have been elaborated. The goal is to ship LN to the LBT in 2014.
LINC-NIRVANA (LN) is the near-infrared, Fizeau-type imaging interferometer for the Large Binocular Telescope
(LBT) on Mt. Graham, Arizona, USA (3267m of elevation). The instrument is currently being built by a consortium of
German and Italian institutes under the leadership of the Max Planck Institute for Astronomy (MPIA) in Heidelberg,
Germany. It will combine the radiation from both 8.4m primary mirrors of LBT in such a way that the sensitivity of a
11.9m telescope and the spatial resolution of a 22.8m telescope will be obtained within a 10.5arcsec x 10.5arcsec
scientific field of view. Interferometric fringes of the combined beams are tracked in an oval field with diameters of 1
and 1.5arcmin. In addition, both incoming beams are individually corrected by LN’s multi-conjugate adaptive optics
(MCAO) system to reduce atmospheric image distortion over a circular field of up to 6arcmin in diameter.
This paper gives a comprehensive technical overview of the instrument comprising the detailed design of LN’s four
major systems for interferometric imaging and fringe tracking, both in the NIR range of 1 - 2.4μm, as well as
atmospheric turbulence correction at two altitudes, both in the visible range of 0.6 - 0.9μm. The resulting performance
capabilities and a short outlook of some of the major science goals will be presented. In addition, the roadmap for the
related assembly, integration and verification (AIV) process will be discussed. To avoid late interface-related risks,
strategies for early hardware as well as software interactions with the telescope have been elaborated. The goal is to ship
LN to the LBT in 2014.
MOONS is a new conceptual design for a multi-object spectrograph for the ESO Very Large Telescope (VLT)
which will provide the ESO astronomical community with a powerful, unique instrument able to serve a wide
range of Galactic, Extragalactic and Cosmological studies. The instrument foresees 1000 fibers which can be
positioned on a field of view of 500 square-arcmin. The sky-projected diameter of each fiber is at least 1 arcsec
and the wavelengths coverage extends from 0.8 to 1.8 μm.
This paper presents and discusses the design of the spectrometer, a task which is allocated to the Italian National
Institute of Astrophysics (INAF).
The baseline design consists of two identical cryogenic spectrographs. Each instrument collects the light from
over 500 fibers and feeds, through dichroics, 3 spectrometers covering the "I" (0.79-0.94 μm), "YJ" (0.94-1.35
μm) and "H" (1.45-1.81 μm) bands.
The low resolution mode provides a complete spectrum with a resolving power ranging from R'4,000 in the
YJ-band, to R'6,000 in the H-band and R'8,000 in the I-band. A higher resolution mode with R'20,000 is
also included. It simultaneously covers two selected spectral regions within the J and H bands.
During the last years, a number of telescopes and instruments have been dedicated to the follow-up of GRBs: recent
studies of the prompt emission (see for instance GRB080319B) and of their afterglows, evidenced a series of phenomena
that do not fit very well within the standard fireball model. In those cases, optical observations were fundamental to
distinguish among different emission mechanisms and models. In particular, simultaneous observation in various optical
filters became essential to understand the physics, and we discovered the need to have a detailed high time resolution follow up. Finally, recent observations of the polarization in GRB 090102 clearly indicate the presence of an ordered
magnetic field favoring the electromagnetic outflows models. This is, however, only one case and, in order to detail
properly the model, we need a bit of statistics. But, after the Swift launch, the average observed intensity of GRB
afterglows showed to be lower than thought before. Robotic telescopes, as demonstrated by REM, ROTSE, TAROT, etc.
(but see also the GROND set up) is clearly the winning strategy. Indeed, as we will also briefly discuss later on, the
understanding of the prompt emission mechanism depends on the observations covering the first few hundreds seconds
since the beginning of the event with high temporal resolution. To tackle these problems and track down a realistic
model, we started the conceptual design and phase A study of a 4 meter class, fast-pointing telescope (40 sec on target),
equipped with multichannel imagers, from Visible to Near Infrared (Codevisir/Pathos). In the study we explored all the
different parts of the project, from the telescope to the instrumental suite to data managing and analysis, to the dome and
site issue. Contacts with industry have been fruitful in understanding the actual feasibility of building such a complex
machine and no show stoppers have been identified, even if some critical points should be better addressed in the Phase
B study. In this paper, we present the main results of the feasibility study we performed.
LINC-NIRVANA is the IR Fizeau interferometric imager that will be installed within a couple of years on the Large
Binocular Telescope (LBT) in Arizona. Here we present a particular sub-system, the so-called Patrol Camera (PC),
which has been now completed, along with the results of the laboratory tests. It images (in the range 600-900 nm) the
same 2 arcmin FoV seen by the Medium-High Wavefront Sensor (MHWS), adequately sampled to provide the MHWS
star enlargers with the positions of the FoV stars with an accuracy of 0.1 arcsec. To this aim a diffraction-limited
performance is not required, while a distortion free focal plane is needed to provide a suitable astrometric output. Two
identical systems have been realized, one for each single arm, which corresponds to each single telescope. We give here
the details concerning the optical and mechanical layout, as well as the CCD and the control system. The interfaces (mainly software procedures) with LINC-NIRVANA (L-N) are also presented.
A new mechanical interface between the telescope Nasmyth derotator and the focal plane instrumentation has been
developed and built for the robotic REM telescope in La Silla. A light-weighted flange will substitute the existing one in
order to improve performances in term of mechanical flexures. A new ghost-free, high performances, dichroic has been
designed and installed inside the new mechanical flange, improving the efficiency of the wavelength splitting between
the visible and the near-infrared channels. The visible camera has been completely redesigned in order to get
simultaneous multi-band coverage within the existing 10'x10' field of view. Four bands will be observed onto the same
2kx2k, 13.5 micron pixel, detector. Band splitting is obtained with plate dichroics, working at 45 deg of incidence angle.
It will allow to fast observe gamma-ray burst afterglow from the 400 nm up to 2.5 micron, to better characterize spectral
features of these fastly evolving sources.
LINC-NIRVANA is an infrared camera that will work in Fizeau interferometric way at the Large Binocular Telescope (LBT). The two beams that will be combined in the camera are corrected by an MCAO system, aiming to cancel the turbulence in a scientific field of view of 2 arcminutes. The MCAO wavefront sensors will be two for each arm, with the task to sense the atmosphere at two different altitudes (the ground one and a second height variable between a few kilometers and a maximum of 15 kilometers). The first wavefront sensor, namely the Ground layer Wavefront sensor (GWS), will drive the secondary adaptive mirror of LBT, while the second wavefront sensor, namely the Mid High layer Wavefront Sensor (MHWS) will drive a commercial deformable mirror which will also have the possibility to be conjugated to the same altitude of the correspondent wavefront sensor. The entire system is of course duplicated for the two telescopes, and is based on the Multiple Field of View (MFoV) Layer Oriented (LO) technique, having thus different FoV to select the suitable references for the two wavefront sensor: the GWS will use the light of an annular field of view from 2 to 6 arcminutes, while the MHWS will use the central 2 arcminutes part of the FoV. After LINC-NIRVANA has accomplished the final design review, we describe the MFoV wavefront sensing system together with its current status.
REMIR is the NIR camera of the automatic REM (Rapid Eye Mount) Telescope located at ESO-La Silla Observatory (Chile) and dedicated to monitor the afterglow of Gamma Ray Burst events. During the last two years, the REMIR camera went through a series of cryogenics problems, due to the bad functioning of the Leybold cryocooler Polar SC7. Since we were unable to reach with Leybold for a diagnosis and a solution for such failures, we were forced to change drastically the cryogenics of REMIR, going from cryocooler to LN2: we adopted an ad-hoc modified Continuous Flow Cryostat, a cryogenics system developed by ESO and extensively used in ESO instrumentation, which main characteristic is that the LN2 vessel is separated from the cryostat, allowing a greater LN2 tank, then really improving the hold time. In this paper we report the details and results of this operation.
LINC-NIRVANA is the IR Fizeau interferometric imager of the Large Binocular Telescope (LBT) in Arizona.
Here we describe in particular the design, realization and preliminary tests of the so-called Patrol Camera. It
can image (in the range 600-900 nm) the same 2 arcmin FoV seen by the Medium- High-Wavefront Sensor
(MHWS), adequately sampled to provide the MHWS star enlargers with the positions of the FoV stars with
an accuracy of 0.1 arcsec. To this aim a diffraction-limited performance is not required, while a distortion free
focal plane is needed to provide a suitable astrometric output. Two identical systems will be realized, one for
each single arm, which corresponds to each single telescope. We give here the details concerning the optical
and mechanical design, as well as the CCD and the control system. The interfaces with LINC-NIRVANA are
also presented both in terms of matching the carbon fiber optical bench and developing of suitable software
procedures. Since the major components have been already gathered, the laboratory tests and the integration
are currently in progress.
REMIR is the NIR camera of the automatic REM (Rapid Eye Mount) Telescope located at ESO La Silla Observatory -
Chile and dedicated to monitor the afterglow of Gamma Ray Burst events. The REMIR camera is composed by a set of
sub systems: the array controller, the cooling system, the temperature and the pressure monitors, the filter wheel
controller, the dither wedge controller. During 2005, a complete re-writing of the REMIR software control system started
in order to optimize the system performances: the new configuration will adopt a client server architecture, where a
supervisor system accepts via socket the data acquisition queries from AQUA (the acquisition data suite), manages the
several components of the camera and the communication with the telescope control system. Here we describe in
particular the philosophy adopted to realize the general control system, the sub systems and the communication
During the early Summer 2003, the REM telescope has been installed at La Silla, together with the near infrared camera REM-IR and the optical spectrograph. ROSS. The REM project is a fully automated instrument to follow-up Gamma Ray Burst, triggered mainly by satellites, such as HETE II, INTEGRAL, AGILE and SWIFT. REM-IR will perform high efficiency imaging of the prompt infrared afterglow of GRB and, together with the optical spectrograph ROSS, will cover simultaneously a wide wavelength range, allowing a better understanding of the intriguing scientific case of GRB.
In this paper we present the result of the commissioning phase of the near infrared camera REM-IR, lasted for an extended period of time and currently under the final fine tuning.
We describe the procedures adopted to realize the fiber unit for feeding the near IR multi-object spectrometer GOHSS. Since a scarce literature is available on this subject, all the steps of the fabrication processes are explained and documented through a detailed illustrative material: in particular the polishing methods of the fiber ends are addressed along with the criteria for evaluating the achieved results; the preparation and application of the ferrules; the matching with the input micro-lens; finally, the laboratory tests to measure the focal ratio degradation of each fiber are presented aiming also to certify the quality of the realized device.
We describe the current status and technical aspects of the GOHSS (Galileo OH Subtracted Spectrograph) project. Here we point out the most critical items and how we have implemented innovative technical solutions to fulfill the compelling requirements imposed by both the optical tolerances and the demands of a high sensitivity. In particular we examine the camera lens mechanics realized in ultra low expansion quartz; the refrigerator system; the IR array mount realized in an unconventional way; the effort put in procuring optical devices with quite large efficiencies. We are also developing the data reduction package along with the instrument simulator: the optimized procedures and the results on the visibility function of galaxies are given as well. Currently the instrument is in the integration phase at the laboratories of the Astronomical Observatory of Rome and the commissioning phase at the telescope is expected to start at the beginning of year 2003.
We present the main characteristics and astronomical results of SWIRCAM, a NIR imager-spectrometer mainly devoted to the search for extragalactic Supernovae, in the frame of the SWIRT project, a joint scientific collaboration among the Astronomical Observatories of Rome, Teramo and Pulkovo. The camera is currently at the focal plane of the AZT-24 1.1 m telescope at the Observing Station of Campo Imperatore, operated by the Astronomical Observatory of Rome. SWIRCAM saw its first light during December 1998 and it is currently employed for both the SWIRT operative phase and other institutional projects.
We describe the current status of the technical aspects of the GOHSS project. It consists of a fiber-fed NIR spectrograph for faint objects. It will be a second-light instrument for the Nasmyth focus of the 3.5m Galileo telescope located on La Palma. GOHSS is an innovative instrument which accomplishes OH night-sky subtraction, differently from the hardware solution used by other devices; it provides a multiechelle design with software OH subtraction capable of yielding about 25 spectra in the z,J and H bands at an effective spectral resolution of about 4000, which is necessary to strongly reduce the impact of atmospheric OH lines. The GOHSS design is completed and the operative phase is already started through the procurement of the most important components. We have also started to develop the data reduction package for the instrument and the first result of the 1D approach as presented.
In this paper we present the new optical camera ROSI mounted at the 60/90/180 Schmidt telescope of the Campo Imperatore Station. We have developed a new LN2 compact cryostat designed to be mounted directly at the internal focus of the telescope and optimized to obtain a very long duration of the cryogenic liquid. The instrument is based on a 2K by 2K thinned EEV cooled down to 180K and despite of the reduced capacity of the vessel the overall holding time of LN2 is greater than 10 hours, providing a long working cycle. The CCD is controlled by a modified version of the Astrocam DUO provided by LSR that offers both a high readout speed and a low noise. ROSI has been equipped with the same high transmission filter set use din SUSI2 provided by CETEV. The computer design of the entire instrument allows a negligible obscure of the light path, comparable to the traditional one of the Schmidt telescopes equipped with photographic plates.
Telescope, dome and camera controls can be seen as independent systems managed by an ad hoc software. We have used both hardware intelligence and a distributed PC based software to produce a system performing interactive and automatic observations. An integrated and automated data reduction pipeline allows most almost real-time image processing and WEB searchable archiving.