The CARMENES instrument is a pair of high-resolution (R⪆80,000) spectrographs covering the wavelength range from 0.52 to 1.71 μm, optimized for precise radial velocity measurements. It was installed and commissioned at the 3.5m telescope of the Calar Alto observatory in Southern Spain in 2015. The first large science program of CARMENES is a survey of ~ 300 M dwarfs, which started on Jan 1, 2016. We present an overview of all subsystems of CARMENES (front end, fiber system, visible-light spectrograph, near-infrared spectrograph, calibration units, etalons, facility control, interlock system, instrument control system, data reduction pipeline, data flow, and archive), and give an overview of the assembly, integration, verification, and commissioning phases of the project. We show initial results and discuss further plans for the scientific use of CARMENES.
We present an overview of the 4MOST project at the Preliminary Design Review. 4MOST is a major new wide-field, high-multiplex spectroscopic survey facility under development for the VISTA telescope of ESO. 4MOST has a broad range of science goals ranging from Galactic Archaeology and stellar physics to the high-energy physics, galaxy evolution, and cosmology. Starting in 2021, 4MOST will deploy 2436 fibres in a 4.1 square degree field-of-view using a positioner based on the tilting spine principle. The fibres will feed one high-resolution (R~20,000) and two medium resolution (R~5000) spectrographs with fixed 3-channel designs and identical 6k x 6k CCD detectors. 4MOST will have a unique operations concept in which 5-year public surveys from both the consortium and the ESO community will be combined and observed in parallel during each exposure. The 4MOST Facility Simulator (4FS) was developed to demonstrate the feasibility of this observing concept, showing that we can expect to observe more than 25 million objects in each 5-year survey period and will eventually be used to plan and conduct the actual survey.
4MOST (4-meter Multi-Object Spectroscopic Telescope) is a wide-field, fiber-feed, high-multiplex spectroscopic survey facility to be installed on the 4-meter ESO telescope VISTA in Chile. It consists of two identical low resolution spectrographs and one high resolution spectrograph. The instrument is presently in the preliminary design phase and expected to get operational end of 2022. The high resolution spectrograph will afford simultaneous observations of up to 812 targets - over a hexagonal field of view of ~ 4.1 sq.degrees on sky - with a spectral resolution R>18,000 covering a wavelength range from 393 to 679nm in three channels. In this paper we present the optical and mechanical design of the high resolution spectrograph (HRS) as prepared for the review at ESO, Garching. The expected performance including the highly multiplexed fiber slit concept is simulated and its impact on the optical performance given. We show the thermal and finite element analyses and the resulting stability of the spectrograph under operational conditions.
CARMENES is a fiber-fed high-resolution Echelle spectrograph for the Calar Alto 3.5m telescope. The instrument is built by a German-Spanish consortium under the lead of the Landessternwarte Heidelberg. The search for planets around M dwarfs with a radial velocity of 1 m/s is the main focus of the planned science. Two channels, one for the visible, another for the near-infrared, will allow observations in the complete wavelength range from 550 to 1700 nm. To ensure the stability, the instrument is working in vacuum in a thermally controlled environment. The VIS channel spectrograph is covering the visible wavelength range from 0.55 to 0.95 μm with a spectral resolution of R=93,400 in a thermally and pressure-wise very stable environment. The VIS channel spectrograph started science operation in January 2016. Here we present the opto-mechanical and system design of the channel with the focus on the (re-)integration phase at the observatory and the measured performance during the testing and commissioning periods, including the lessons learned.
The Waltz Spectrograph is a fiber-fed high-resolution échelle spectrograph for the 72 cm Waltz Telescope at the Landessternwarte, Heidelberg. It uses a 31.6 lines/mm 63.5° blaze angle échelle grating in white-pupil configuration, providing a spectral resolving power of R ~ 65,000 covering the spectral range between 450-800nm in one CCD exposure. A prism is used for cross-dispersion of échelle orders. The spectrum is focused by a commercial apochromat onto a 2k×2k CCD detector with 13.5μm per pixel. An exposure meter will be used to obtain precise photon-weighted midpoints of observations, which will be used in the computation of the barycentric corrections of measured radial velocities. A stabilized, newly designed iodine cell is employed for measuring radial velocities with high precision. Our goal is to reach a radial velocity precision of better than 5 m/s, providing an instrument with sufficient precision and sensitivity for the discovery of giant exoplanets. Here we describe the design of the Waltz spectrograph and early on-sky results.
CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs) is an instrument consistent in two ultra-stable high resolution (R~82,000) spectrographs covering simultaneously the visible (0.5 – 1.0μm) and near-IR (1.0 - 1.7μm) ranges to provide high-accuracy radial-velocity measurements (∼1 m/s) thanks to the long-term stability. CARMENES was the initiative of a consortium of eleven German and Spanish institutions. CARMENES has been built for the 3.5m telescope at the Centro Astronómico Hipano- Alemán (CAHA), Calar Alto Observatory (Almería, Spain) and is currently in operation. CAHA is jointly operated by the Max-Planck-Society (MPG) and the Spanish National Research Council (CSIC).
The project received the green light in October 2010 and in February 2013 passed a Final Design Review. Six months later, the MPG and CSIC, the observatory’s owners, made an independent evaluation concluding that CARMENES had to be ready for operations at the end of 2015. Since then, fulfilling the calendar was the driver of all project decisions. Moreover, the observatory’s survival was linked to the instrument’s success: should the instrument fail, the observatory would be closed. On the contrary, the instrument’s success would give unique capabilities to the Observatory for Big Science. Such a challenge became to be our private Olympic Games: we had to be on time. This decision definitively impacted on the project dynamics, there was no room for a delay. The deadline, December 31st, 2015, was controlled by a strict tracking of the critical path; calendar deviations were corrected with risky decisions while fast tracking or even crashing methods were applied.
The management scenario was far from optimum: most key people in the project shared their time with other duties; the observatory funding cuts; the budget was tight and distributed among the 11 partner centers with their own different rules, etc. Despite these difficulties, the close coordination among the project manager, the system engineer and the work package managers, the hard work of the whole team, and the support from the observatory were our best bets.
Two frenetic years after the calendar decision, we had manufactured, integrated and tested the two spectrographs and we were commissioning the instrument. The instrument first light took place on November, 9th, 2015 and CARMENES entered in operation at the end of December 2015. This paper describes the keys to success.
The 4-m Multi-Object Spectrographic Telescope (4MOST) is one high-resolution (R ~ 18000) and two lowresolution (R fi 5000) spectrographs covering the wavelength range between 390 and 950 nm. The spectrographs will be installed on ESO VISTA telescope and will be fed by approximately 2400 fibres. The instrument is capable to simultaneously obtain spectra of about 2400 objects distributed over an hexagonal field-of-view of four square degrees. This paper aims at giving an overview of the control software design, which is based on the standard ESO VLT software architecture and customised to fit the needs of the 4MOST instrument. In particular, the facility control software is intended to arrange the precise positioning of the fibres, to schedule and observe many surveys in parallel, and to combine the output from the three spectrographs. Moreover, 4MOST's software will include user-friendly graphical user interfaces that enable users to interact with the facility control system and to monitor all data-taking and calibration tasks of the instrument. A secondary guiding system will be implemented to correct for any fibre exure and thus to improve 4MOST's guiding performance. The large amount of fibres requires the custom design of data exchange to avoid performance issues. The observation sequences are designed to use spectrographs in parallel with synchronous points for data exchange between subsystems. In order to control hardware devices, Programmable Logic Controller (PLC) components will be used, the new standard for future instruments at ESO.
The 4MOST instrument is a concept for a wide-field, fibre-fed high multiplex spectroscopic instrument facility on the
ESO VISTA telescope designed to perform a massive (initially >25x106 spectra in 5 years) combined all-sky public
survey. The main science drivers are: Gaia follow up of chemo-dynamical structure of the Milky Way, stellar radial
velocities, parameters and abundances, chemical tagging; eROSITA follow up of cosmology with x-ray clusters of
galaxies, X-ray AGN/galaxy evolution to z~5, Galactic X-ray sources and resolving the Galactic edge;
Euclid/LSST/SKA and other survey follow up of Dark Energy, Galaxy evolution and transients. The surveys will be
undertaken simultaneously requiring: highly advanced targeting and scheduling software, also comprehensive data
reduction and analysis tools to produce high-level data products. The instrument will allow simultaneous observations of
~1600 targets at R~5,000 from 390-900nm and ~800 targets at R<18,000 in three channels between ~395-675nm
(channel bandwidth: 45nm blue, 57nm green and 69nm red) over a hexagonal field of view of ~ 4.1 degrees. The initial
5-year 4MOST survey is currently expect to start in 2020. We provide and overview of the 4MOST systems: optomechanical,
control, data management and operations concepts; and initial performance estimates.
4MOST is a wide-field, high-multiplex spectroscopic survey facility under development for the VISTA telescope of the European Southern Observatory (ESO). Its main science drivers are in the fields of galactic archeology, high-energy physics, galaxy evolution and cosmology. 4MOST will in particular provide the spectroscopic complements to the large
area surveys coming from space missions like Gaia, eROSITA, Euclid, and PLATO and from ground-based facilities like VISTA, VST, DES, LSST and SKA. The 4MOST baseline concept features a 2.5 degree diameter field-of-view with ~2400 fibres in the focal surface that are configured by a fibre positioner based on the tilting spine principle. The fibres feed two types of spectrographs; ~1600 fibres go to two spectrographs with resolution R<5000 (λ~390-930 nm) and
~800 fibres to a spectrograph with R>18,000 (λ~392-437 nm and 515-572 nm and 605-675 nm). Both types of spectrographs are fixed-configuration, three-channel spectrographs. 4MOST will have an unique operations concept in which 5 year public surveys from both the consortium and the ESO community will be combined and observed in parallel during each exposure, resulting in more than 25 million spectra of targets spread over a large fraction of the
southern sky. The 4MOST Facility Simulator (4FS) was developed to demonstrate the feasibility of this observing
concept. 4MOST has been accepted for implementation by ESO with operations expected to start by the end of 2020.
This paper provides a top-level overview of the 4MOST facility, while other papers in these proceedings provide more
detailed descriptions of the instrument concept, the instrument requirements development, the systems engineering implementation, the instrument model, the fibre positioner concepts, the fibre feed, and the spectrographs.
This paper gives an overview of the CARMENES instrument and of the survey that will be carried out with it
during the first years of operation. CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths
with Near-infrared and optical Echelle Spectrographs) is a next-generation radial-velocity instrument
under construction for the 3.5m telescope at the Calar Alto Observatory by a consortium of eleven Spanish
and German institutions. The scientific goal of the project is conducting a 600-night exoplanet survey targeting
~ 300 M dwarfs with the completed instrument.
The CARMENES instrument consists of two separate echelle spectrographs covering the wavelength range
from 0.55 to 1.7 μm at a spectral resolution of R = 82,000, fed by fibers from the Cassegrain focus of the telescope.
The spectrographs are housed in vacuum tanks providing the temperature-stabilized environments necessary to
enable a 1 m/s radial velocity precision employing a simultaneous calibration with an emission-line lamp or with
a Fabry-Perot etalon. For mid-M to late-M spectral types, the wavelength range around 1.0 μm (Y band) is the
most important wavelength region for radial velocity work. Therefore, the efficiency of CARMENES has been
optimized in this range.
The CARMENES instrument consists of two spectrographs, one equipped with a 4k x 4k pixel CCD for
the range 0.55 - 1.05 μm, and one with two 2k x 2k pixel HgCdTe detectors for the range from 0.95 - 1.7μm.
Each spectrograph will be coupled to the 3.5m telescope with two optical fibers, one for the target, and one
for calibration light. The front end contains a dichroic beam splitter and an atmospheric dispersion corrector,
to feed the light into the fibers leading to the spectrographs. Guiding is performed with a separate camera;
on-axis as well as off-axis guiding modes are implemented. Fibers with octagonal cross-section are employed to
ensure good stability of the output in the presence of residual guiding errors. The fibers are continually actuated
to reduce modal noise. The spectrographs are mounted on benches inside vacuum tanks located in the coud´e
laboratory of the 3.5m dome. Each vacuum tank is equipped with a temperature stabilization system capable
of keeping the temperature constant to within ±0.01°C over 24 hours. The visible-light spectrograph will be
operated near room temperature, while the near-IR spectrograph will be cooled to ~ 140 K.
The CARMENES instrument passed its final design review in February 2013. The MAIV phase is currently
ongoing. First tests at the telescope are scheduled for early 2015. Completion of the full instrument is planned
for the fall of 2015. At least 600 useable nights have been allocated at the Calar Alto 3.5m Telescope for the
CARMENES survey in the time frame until 2018.
A data base of M stars (dubbed CARMENCITA) has been compiled from which the CARMENES sample can
be selected. CARMENCITA contains information on all relevant properties of the potential targets. Dedicated imaging, photometric, and spectroscopic observations are underway to provide crucial data on these stars that
are not available in the literature.
CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs) is a next-generation instrument for the 3.5m telescope at the Calar Alto Observatory, built by a consortium of eleven Spanish and German institutions. The CARMENES instrument consists of two separate échelle spectrographs covering the wavelength range from 0.55 μm to 1.7 μm at a spectral resolution of R = 82, 000, fed by fibers from the Cassegrain focus of the telescope. Both spectrographs are housed in temperature-stabilized vacuum tanks, to enable a long-term 1 m/s radial velocity precision employing a simultaneous calibration with Th-Ne and U-Ne emission line lamps. CARMENES has been optimized for a search for terrestrial planets in the habitable zones (HZs) of low-mass stars, which may well provide our first chance to study environments capable of supporting the development of life outside the Solar System. With its unique combination of optical and near-infrared ´echelle spectrographs, CARMENES will provide better sensitivity for the detection of low-mass planets than any comparable instrument, and a powerful tool for discriminating between genuine planet detections and false positives caused by stellar activity. The CARMENES survey will target 300 M dwarfs in the 2014 to 2018 time frame.
The overall purpose of the CARMENES instrument is to perform high-precision measurements of radial velocities of
late-type stars with long-term stability. CARMENES will be installed in 2014 at the 3.5 m telescope in the German-
Spanish Astronomical Center at Calar Alto observatory (CAHA, Spain) and will be equipped with two spectrographs in
the near-infrared and visible windows. The technology involved in such instrument represents a challenge at all levels.
The instrument coordination and management is handled by the Instrument Control System (ICS), which is responsible
of carrying out the operations of the different subsystems and providing a tool to operate the instrument from low to high
user interaction level. The main goal of the ICS and the CARMENES control layer architecture is to maximize the
instrument efficiency by reducing time overheads and by operating it in an integrated manner. The ICS implements the
CARMENES operational design. A description of the ICS architecture and the application programming interfaces for
low- and high-level communication is given. Internet Communications Engine is the technology selected to implement
most of the interface protocols.
CARMENES is a fiber-fed high-resolution échelle spectrograph for the Calar Alto 3.5m telescope. The instrument is
built by a German-Spanish consortium under the lead of the Landessternwarte Heidelberg. The search for planets around
M dwarfs with a radial velocity accuracy of 1 m/s is the main focus of the planned science. Two channels, one for the
visible, another for the near-infrared, will allow observations in the complete wavelength range from 550 to 1700 nm. To
ensure the stability, the instrument is working in vacuum in a thermally controlled environment. The optical design of
both channels of the instrument and the front-end, as well as the opto-mechanical design, are described.
The CARMENES project, which is currently at FDR stage, is a last-generation exoplanet hunter instrument to be
installed in the Calar Alto Observatory by 2014. It is split into two different spectrographs: one works within the visual
range while the other does it in the NIR range. Both channels need to be extremely stable in terms of mechanical and
thermal behavior. Nevertheless, due to the operation temperature of the NIR spectrograph, the thermal stability
requirement (±0.07 K in 24 hours; ±0.01 K (goal)) becomes actually a major challenge. The solution here proposed
consists of a system that actively cools a shield enveloping the optical bench. Thus, the instability produced on the shield
temperature is further damped on the optical bench due to the high mass of the latter, as well as the high thermal
decoupling between both components, the main heat exchange being produced by radiation.
This system -which is being developed with the active collaboration and advice of ESO (Jean-Louis Lizon)- is composed
by a previous unit which produces a stable flow of nitrogen gas. The flow so produced goes into the in-vacuum circuitry
of the NIR spectrograph and removes the radiative heat load incoming to the radiation shield by means of a group of
properly dimensioned heat exchangers.
The present paper describes and summarizes the cooling system designed for CARMENES NIR as well as the analyses
Currently, every single instrument using NIR detectors is cooled down to cryogenic temperatures to minimize the
thermal flux emitted by a warm instrument. Cryogenization, meaning reaching very low operating temperatures, is a
must when the K band is needed for the science case. This results in more complex and more expensive instruments.
However, science cases that do not benefit from observing in the K band, like the detection of exoplanets around M
dwarfs through the radial velocity technique, can make use of non-cryogenic instruments. The CARMENES instrument
is implementing a cooling system which could allow such a solution. It is being built by a consortium of eleven Spanish
and German institutions and will conduct an exoplanet survey around M dwarfs. Its concept includes two spectrographs,
one equipped with a CCD for the range 550-950 nm, and one with HgCdTe detectors for the range from 950-1700 nm,
covering therefore the YJH bands.
In this contribution, different possibilities are studied to reach the final cooling solution to be used in CARMENES, all of
them demonstrated to be feasible, within the requirements of the SNR requested by the science case.
LUCIFER 1 is the rst of two identical camera-spectrograph units installed at the LBT (Large Binocular Telescope)
on Mount Graham in Arizona. Its commissioning took place between September 2008 and November
2009 and has immediately been followed by science operations since December 2009.
LUCIFER has a 4x4 arcminute eld of view. It is equipped with a 2048x2048 pixel HAWAII-2 array, suitable
lters (broad-band z, J, H, K & Ks plus 12 medium and narrow band near-infrared lters) and three gratings for
spectroscopy for a resolution of up to 15000. LUCIFER has 3 cameras: two specic for seeing limited imaging
(the N3.75 camera, with 0.12"/pixel) and spectroscopy (the N1.8 camera, with 0.25"/pixel) and one for diraction
limited observations (the N30 camera). We report here about the completed seeing-limited commissioning, thus
using only two of the cameras.
CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical
Echelle Spectrographs) is a next-generation instrument to be built for the 3.5m telescope at the Calar Alto
Observatory by a consortium of Spanish and German institutions. Conducting a five-year exoplanet survey
targeting ~ 300 M stars with the completed instrument is an integral part of the project. The CARMENES
instrument consists of two separate spectrographs covering the wavelength range from 0.52 to 1.7 μm at a spectral
resolution of R = 85, 000, fed by fibers from the Cassegrain focus of the telescope. The spectrographs are housed
in a temperature-stabilized environment in vacuum tanks, to enable a 1m/s radial velocity precision employing
a simultaneous ThAr calibration.
LUCIFER is a NIR spectrograph and imager (wavelength range 0.9 to 2.5 micron) for the Large Binocular
Telescope (LBT) on Mt. Graham, Arizona, working at cryogenic temperatures of less than 70K. Two instruments
are built by a consortium of five German institutes and will be mounted at the bent Gregorian foci of the two
individual telescope mirrors. Three exchangable cameras are available for imaging and spectroscopy: two of
them are optimized for seeing-limited conditions, a third camera for the diffraction limited case will be used with
the LBT adaptive secondary mirror working. Up to 33 exchangeable masks are available for longslit or multi-object
spectroscopy (MOS) over the full field of view (FOV). Both MOS-units (LUCIFER 1 and LUCIFER
2) and the auxiliary cryostats together with the control electronics have been completed. The observational
software-package is in its final stage of preparation.
After the total integration of LUCIFER 1 extensive tests were done for all electro-mechanical functions and
the verification of the instrument started. The results of the tests are presented in detail and are compared with
LUCIFER (LBT NIR Spectrograph Utility with Camera and Integral-Field
Unit for Extragalactic Research) is a NIR spectrograph and imager for
the LBT (Large Binocular Telescope) working in the wavelength range from 0.9 to 2.5 microns. Two instruments are built by a consortium of
five German institutes (Landessternwarte Heidelberg (LSW), Max Planck
Institut for Astronomy (MPIA), Max Planck Institut for Extraterrestric Physics (MPE), Astronomical Institut of the Ruhr-University Bochum (AIRUB) and Fachhochschule for Technics and Design Mannheim (FHTG).
All major components for the first instrument have been manufactured or are in the final stage of procurement. While integration and testing of LUCIFER 1 started in spring 2006 at the MPIA in Heidelberg, the cryostat for LUCIFER 2 has been sent to the MPE in Garching for system integration tests of the MOS-unit and testing of the mask cabinet exchange. The control electronics for the basic instrument has been manufactured, the MOS control electronics has been integrated and is being debugged. The MOS control software is under development by AIRUB. Fabrication and integration of components for LUCIFER 2 have started.
Lucifer VR is a virtually realized instrument that was build in order to allow improved pre-integration software tests,
training of observers as well as providing educational access. Beside testing the instrument hardware in combination with
e.g. a telescope simulator, software tests need to be done. A virtual instrument closes the gap between regression tests
and testing the control software with the integrated instrument. Lucifer VR allows much earlier tests and reduces the
amount of time needed to combine the software with the hardware. By modeling the instrument in a simulator, motion
times can be calculated very easily and the position of all instrument units can be traced. Especially when using complex
mechanisms like a MOS unit a virtual instrument makes software development less time consuming. Lucifer VR consists
of three parts; one for handling the communication, another to simulate the hardware and finally a part to visualize the
whole instrument in three dimensions.
The LUCIFER instrument is a near infrared spectrograph/imager with MOS for the Large Binocular Telescope.
Here we present the final software design, the interrelation of the software packages and the used hardware
architecture. The software package is completely running under Java using intensively its Remote Method
Invocation (RMI) mechanisms in a distributed system environment. The use of Java helped us to cope with a
small amount of available manpower for the SW development, providing many native built-in Java methods and
classes, which speed up the development process a lot. The control software will be finally installed on a Solaris
OS, hosted on a Sun Fire V880 server, which results from a specific hardware constraint. For testing purposes a
standard Linux environment is used. This shows another big Java advantage, the platform independency. The
"First Light" of LUCIFER 1 is estimated for summer/fall 2007, following LUCIFER 2 one year later.
LUCIFER (LBT NIR Spectrograph Utility with Camera and Integral-Field
Unit for Extragalactic Research) is a NIR spectrograph and imager for
the LBT (Large Binocular Telescope) working in the wavelength range from 0.9 to 2.5 microns. The instrument is to be built by a consortium of five german institutes (Landessternwarte Heidelberg (LSW), Max Planck Institut for Astronomy (MPIA), Max Planck Institut for Extraterrestric Physics (MPE), Astronomical Institut of the Ruhr-University Bochum (AIRUB) and Fachhochschule for Technics and Design Mannheim (FHTG)). LUCIFER will be one of the first light instruments of the LBT and will be available to the community at the end of 2005. A copy of the instrument for the second LBT mirror follows about one year later.
The paper presents a brief status report of the procured and built
hardware, of the workpackages already carried out and summarizes the ongoing work in progress.
LUCIFER (LBT NIR-Spectroscopic Utility with Camera and Integral-Field Unit for Extragalactic Research) is a NIR spectrograph and imager (wavelength range 0.9 to 2.5 micron) for the Large Binocular Telescope (LBT) on Mt. Graham, Arizona. It is built by a consortium of five German institutes and will be one of the first light instruments for the LBT. Later, a second copy for the second mirror of the telescope will follow. Both instruments will be mounted at the bent Gregorian foci of the two individual telescope mirrors. The instrument is equipped with three exchangeable cameras for imaging and spectroscopy: two of them are optimized for seeing-limited conditions, the third camera for the diffraction-limited case with the LBT adaptive secondary mirror working. The spectral resolution will allow for OH suppression. Up to 33 exchangeable masks will be available for longslit and multi-object spectroscopy (MOS) over the full field of view (FOV). The detector will be a Rockwell HAWAII-2 HgCdTe-array.
Extensive tests were done for all the electro-mechanical functions. Those include the grating selection and the grating tilt unit and the drive for the fold mirror to compensate for image movement due to flexure. Furthermore several optical and opto-mechanical units were tested. The procedures and results of the tests are presented in detail and compared with the specifications.
The LUCIFER MOS unit has been designed to exchange long-slit and multi-slit masks between two mask storage cabinets and the focal plane area. In combination with auxiliary cryostats, the MOS unit also permits the exchange of cold mask cabinets between LUCIFER and the auxiliary cryostats. Main functional components of the MOS unit are: a focal plane interface accepting the active mask, a mask handling unit transporting the masks between the focal plane mount and their storage locations, a stationary and an exchangeable cabinet holding 10 longslit and 23 multi-slit masks respectively, the translation drives for the exchangeable cabinet and the mask handling unit, and the mask locking unit securing the masks in their cabinets. For mask cabinet exchange, the LUCIFER cryostat as well as the auxiliary cryostats are equipped with 32 cm clear diameter gate valves. A test cryostat has been built to test all MOS unit functions at LN2 temperature. Most of the MOS unit components have been completed. System tests at ambient have started. First results are presented.
We describe the detector subsystem developed at MPIA to operate the Rockwell Hawaii-2 detectors used in the LUCIFER and LINC-NIRVANA instruments for the Large Binocular Telescope (LBT). To fully exploit the capabilities of the LBT, the detector subsystem must meet, especially in the case of the low background applications foreseen for LUCIFER, very stringent requirements in terms of stability and read noise. A read-out electronics has been developed at MPIA, which is able to read the 32 outputs of the Hawaii-2 detector, as well as the 4 reference signals available in this chip. The noise figure associated to the electronics alone is negligible with respect to the intrinsic read noise of the detector, while the cloking patterns and the value of the bias voltages applied to the chip are optimized in order to maximize the signal to noise ratio
in the different operating modes. We present the results of the tests performed with the LUCIFER science detector; in particular, we
describe the main properties of the detector: read noise, dark current, linearity, and long term stability, and what are the read-out schemes foreseen for different observational modes. We discuss also how the reference outputs can be used in order to correct for thermal drifts, and how effective those outputs are in removing higher frequency noise components.
We present a system for the exchange and handling of cold field masks in LUCIFER, the near infrared camera and spectrograph for the LBT. Inside the LUCIFER cryostat, 10 field-stop and long-slit masks, and 23 multi-slit masks are stored in a stationary and an exchangeable cabinet respectively. With LUCIFER at operating temperature, the exchangeable cabinet with its multi-slit
masks can be transferred from the LUCIFER cryostat to an auxiliary cryostat, and a second cabinet harboring the newly made, pre-cooled masks can be transferred back to LUCIFER from a second
auxiliary cryostat. Inside LUCIFER, a robot transports the individual masks from their storage position in the cabinet to the focal plane and inserts them in a mask mount where they are centered on two pins. The position accuracy of the masks in the focal plane is anticipated to be better than ± 10 μm. A mechanism which locks the masks in their cabinets and releases only the one connected to the transport robot permits mask exchange in arbitrary
orientation of the cryostat.
LUCIFER (LBT NIR-Spectroscopic Utility with Camera and Integral-Field Unit for Extragalactic Research) is a NIR spectrograph and imager for the Large Binocular Telescope (LBT) on Mt. Graham, Arizona. It is built by a consortium of five German institutes and will be one of the first light instruments for the LBT. Later, a second copy for the second mirror of the telescope will follow.
Both instruments will be mounted at the bent Gregorian foci of the two individual telescope mirrors. The final design of the instrument is presently in progress.
LUCIFER will work at cryogenic temperature in the wavelength range from 0.9 μm to 2.5 μm. It is equipped with three exchangeable cameras for imaging and spectroscopy: two of them are optimized for seeing-limited conditions, the third camera for the diffraction-limited
case with the LBT adaptive secondary mirror working. The spectral resolution will allow for OH suppression. Up to 33 exchangeable masks will be available for longslit and multi-object spectroscopy (MOS) over the full field of view (FOV). The detector will be a Rockwell HAWAII-2 HgCdTe-array.
LUCIFER is a full cryogenic NIR spectrograph and imager to be built by a consortium of fiber institutes, Max Planck Institut fuer Astronomie in Heidelberg, Max Planck Institut fuer Extraterrestrische Physik in Garching, Astronomisches Institut der Ruhr Universitaet Bochum and Fachhochschule fuer Technik und Gestaltung in Mannheim. The instrument has been selected as one of three first-light instruments for the Large Binocular Telescope on Mt. Graham, Arizona which first mirror becomes available to the community in early 2003. The second mirror and a second more or less identical spectrograph/imager follows 18 months later. Both LUCIFER instruments will be mounted dat the bent Gregorian foci of the two individual LBT-mirrors and include six observing six observing modes: seeing and diffraction limited imaging, seeing and diffraction limited longslit spectroscopy, seeing limited multi-object spectroscopy and integral-field spectroscopy. The detector will be a Rockwell HAWAII-2 HgCdTe-array with a pixel-size of 18(mu) .
DIVA (deutsches interferometer fuer vielkanalphotometrie und astrometrie) is a project of a small satellite, aiming to measure positions, proper motions, parallaxes and spectra of several million stars. DIVA will carry two Fizea interferometers with a baseline of 100 mm using a novel telescope design. It consists of a Gregory configuration with high secondary magnification and a four-component field lens system at the intermediate focus. We present the optical layout which allows diffraction-limited imaging over a 0.5 degree of view in the wavelength range 400-1000 nm. Critical aspects of the design are discussed. The present status of the project is briefly outlined.