The first generation of ELT instruments includes an optical-infrared high resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion Echelle Spectrograph). ANDES consists of three fibre-fed spectrographs ([U]BV, RIZ, YJH) providing a spectral resolution of ∼100,000 with a minimum simultaneous wavelength coverage of 0.4-1.8 μm with the goal of extending it to 0.35-2.4 μm with the addition of an U arm to the BV spectrograph and a separate K band spectrograph. It operates both in seeing- and diffraction-limited conditions and the fibre-feeding allows several, interchangeable observing modes including a single conjugated adaptive optics module and a small diffraction-limited integral field unit in the NIR. Modularity and fibre-feeding allows ANDES to be placed partly on the ELT Nasmyth platform and partly in the Coudé room. ANDES has a wide range of groundbreaking science cases spanning nearly all areas of research in astrophysics and even fundamental physics. Among the top science cases there are the detection of biosignatures from exoplanet atmospheres, finding the fingerprints of the first generation of stars, tests on the stability of Nature’s fundamental couplings, and the direct detection of the cosmic acceleration. The ANDES project is carried forward by a large international consortium, composed of 35 Institutes from 13 countries, forming a team of almost 300 scientists and engineers which include the majority of the scientific and technical expertise in the field that can be found in ESO member states.
We present an experimental spectrograph based on a new type of a white pupil echelle spectrograph designed for interline sky continuum measurement. This is an application which requires extremely low instrumental scattered light background and high spectral fidelity due to the faintness of the signal and the fact that the night sky is illuminated by bright hydroxyl emission lines from the red-end of visual spectrum through near infrared wavelengths. The conceptual design is a white pupil echelle spectrograph using a single grating in double pass. The xy-plane of the optical beam is rotated between the two consecutive dispersions thus redirecting the scattered ’grating grass’ light from the grating to different direction respective to the spectrum. A mask in the secondary focus prevents this scattered light reaching the camera. The beam rotation is achieved with a normal right-angle prism allowing us to use off-the-shelf optical components and classical geometrical optics to mitigate the issue of hydroxyl airglow emission lines.
The first generation of ELT instruments includes an optical-infrared high resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion Echelle Spectrograph). ANDES consists of three fibre-fed spectrographs (UBV, RIZ, YJH) providing a spectral resolution of ∼100,000 with a minimum simultaneous wavelength coverage of 0.4-1.8 µm with the goal of extending it to 0.35-2.4 µm with the addition of a K band spectrograph. It operates both in seeing- and diffraction-limited conditions and the fibre-feeding allows several, interchangeable observing modes including a single conjugated adaptive optics module and a small diffraction-limited integral field unit in the NIR. Its modularity will ensure that ANDES can be placed entirely on the ELT Nasmyth platform, if enough mass and volume is available, or partly in the Coudé room. ANDES has a wide range of groundbreaking science cases spanning nearly all areas of research in astrophysics and even fundamental physics. Among the top science cases there are the detection of biosignatures from exoplanet atmospheres, finding the fingerprints of the first generation of stars, tests on the stability of Nature’s fundamental couplings, and the direct detection of the cosmic acceleration. The ANDES project is carried forward by a large international consortium, composed of 35 Institutes from 13 countries, forming a team of more than 200 scientists and engineers which represent the majority of the scientific and technical expertise in the field among ESO member states.
The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid instruments (see ref [1]). It operates in the near-IR spectral region (950-2020nm) as a photometer and spectrometer. The instrument is composed of: - a cold (135K) optomechanical subsystem consisting of a Silicon carbide structure, an optical assembly, a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control system - a detection system based on a mosaic of 16 H2RG with their front-end readout electronic. - a warm electronic system (290K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the spacecraft via a 1553 bus for command and control and via Spacewire links for science data This paper presents: - the final architecture of the flight model instrument and subsystems - the performances and the ground calibration measurement done at NISP level and at Euclid Payload Module level at operational cold temperature.
At the end of 2021, the ESO council approved the start of the construction phase for a High Resolution Spectrograph for the ELT, formerly known as ELT-HIRES, renamed recently as ANDES (ArmazoNes high Dispersion Echelle Spectrograph). The current initial schedule foresees a 9-years development aimed to bring the instrument on-sky soon after the first-generation ELT instruments. ANDES combines high spectral resolution (up to 100,000), wide spectral range (0.4 µm to 1.8 µm with a goal from 0.35 µm to 2.4 µm) and extreme stability in wavelength calibration accuracy (better than 0.02 m/s rms over a 10-year period in a selected wavelength range) with massive optical collecting power of the ELT thus enabling to achieve possible breakthrough groundbreaking scientific discoveries. The main science cases cover a possible detection of life signatures in exoplanets, the study of the stability of Nature’s physical constants along the universe lifetime and a first direct measurement of the cosmic acceleration. The reference design of this instrument in its extended version (with goals included) foresees 4 spectrographic modules fed by fibers, operating in seeing and diffraction limited (adaptive optics assisted) mode carried out by an international consortium composed by 24 institutes from 13 countries which poses big challenges in several areas. In this paper we will describe the approach we intend to pursue to master management and system engineering aspects of this challenging instrument focused mainly on the preliminary design phase, but looking also ahead towards its final construction.
The Laboratoire d’Astrophysique de Marseille (LAM) is deeply involved in the development and the test of the NISP (Near Infrared Spectro-Photometer) instrument for the ESA EUCLID mission that will be launched in 2020. The goal of the mission is to understand the nature of the dark energy responsible for the accelerating expansion of the Universe. NISP is one of its two instruments operating in the near-IR spectral region (0.9-2μm) to map the geometry of the dark Universe. The integration of the NISP flight model (FM) has been started at LAM to allow its delivery in 2019 to the payload after vibration test and two thermal vacuum test campaigns to demonstrate the performance of the instrument. The thermal vacuum test will take place in ERIOS chamber, a 90m3 chamber developed by LAM to test optical instruments at cryogenics temperature and high vacuum. In addition to the chamber, a full and specialised set of ground support equipment called the Verification Ground System (VGS) is developed to fill the goal of the NISP test campaign. The test campaign combines functional tests of the detectors and wheels, performance tests of the instrument, calibration procedure validation and observations scenario test, all done at LAM. One of the main objectives of the test campaign is the measurement of NISP focus position with respect to the EUCLID object plane. The VGS is made of i) a telescope simulator to simulate the EUCLID telescope for optical performance tests, ii) a thermal environment to simulate the Euclid PLM thermal interfaces, iii) the NISP Electrical GSE (EGSE) to control the instrument during the test and iv) a Metrology Verification System (MVS) to measure the positions of NISP and the telescope simulator during the test. We present the set of GSE developed for NISP and their performance already validated during two blank tests: thermal blank test and metrology blank test. In addition, a blank test with all the VGS parts (thermal, optical, metrology) is scheduled in the coming months to validate the overall performance of this GSE including the telescope simulator. The goal is to measure with a high precision the focus distance of the telescope simulator at cold and the stability of the focus in time, and to demonstrate the functionality of the telescope simulator for NISP test campaign needs. Finally, we describe the thermal vacuum test configuration for the “end to end” test on the NISP flight model foreseen by beginning of 2019.
The Euclid mission objective is to understand why the expansion of the Universe is accelerating through by mapping the geometry of the dark Universe
by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision
program with its launch planned for 2020 (ref [1]).
The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (900-
2000nm) as a photometer and spectrometer. The instrument is composed of:
- a cold (135K) optomechanical subsystem consisting of a Silicon carbide structure, an optical assembly (corrector and camera lens), a filter wheel
mechanism, a grism wheel mechanism, a calibration unit and a thermal control system
- a detection subsystem based on a mosaic of 16 HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a
mechanical focal plane structure made with molybdenum and aluminum. The detection subsystem is mounted on the optomechanical subsystem
structure
- a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the
spacecraft via a 1553 bus for command and control and via Spacewire links for science data
This presentation describes the architecture of the instrument at the end of the phase C (Detailed Design Review), the expected performance, the
technological key challenges and preliminary test results obtained for different NISP subsystem breadboards and for the NISP Structural and Thermal
model (STM).
The ESA mission Euclid is designed to explore the dark side of the Universe. The NISP (Near Infrared Spectro-
Photometer) is one of its two instruments operating in the near-IR spectral region (0.9-2μm), that will be fully integrated
and tested at Laboratory d’Astrophysique de Marseille (LAM) under vacuum and thermal conditions. The test campaign
will regroup functional tests, performance tests, calibration procedure validation and observations scenario test. One of
the main objectives of the test campaign will be the measurement of the focus position of NISP with respect to the
EUCLID object plane. To achieve these tests campaign, a global Ground Support Equipment (GSE) called the
Verification Ground System (VGS) has to be developed. It will be a complex set of GSE integrated in ERIOS chamber
made of: a telescope simulator to simulate the EUCLID telescope and to inject light into NISP, a thermal environment to
be used for NISP thermal balance and verification, a sets of mechanical interfaces to align all the parts into ERIOS
chamber, the NISP Electrical GSE (EGSE) to control the instrument during the test and a metrology system to measure
the positions of the components during the test. We will present the preliminary design and concepts of the VGS and we
will show the main difficulties we have to deal with: design of thermal environment at 80K with 4mK stability, the
development of a metrology system in vacuum, knowledge of the focus position within 150μm in cold, etc. The main
objectives of the NISP test will be explained and how the VGS responds to the test requirement.
The Euclid mission objective is to understand why the expansion of the Universe is accelerating by mapping the geometry of the dark Universe by
investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision
program with its launch planned for 2020.
The NISP (Near Infrared Spectro-Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (0.9-2μm) as a
photometer and spectrometer. The instrument is composed of:
- a cold (135K) optomechanical subsystem consisting of a SiC structure, an optical assembly (corrector and camera lens), a filter wheel mechanism, a
grism wheel mechanism, a calibration unit and a thermal control system
- a detection subsystem based on a mosaic of 16 Teledyne HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K,
integrated on a mechanical focal plane structure made with Molybdenum and Aluminum. The detection subsystem is mounted on the optomechanical
subsystem structure
- a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the
spacecraft via a 1553 bus for command and control and via Spacewire links for science data
This presentation describes the architecture of the instrument at the end of the phase B (Preliminary Design Review), the expected performance, the
technological key challenges and preliminary test results obtained on a detection system demonstration model.
The ORIGIN concept is a space mission with a gamma ray, an X-ray and an optical telescope to observe the gamma ray
bursts at large Z to determine the composition and density of the intergalactic matter in the line of sight. It was an answer
to the ESA M3 call for proposal. The optical telescope is a 0.7-m F/1 with a very small instrument box containing 3
instruments: a slitless spectrograph with a resolution of 20, a multi-imager giving images of a field in 4 bands
simultaneously, and a cross-dispersed Échelle spectrograph giving a resolution of 1000. The wavelength range is 0.5 μm
to 1.7 μm. All instruments fit together in a box of 80 mm x 80 mm x 200 mm. The low resolution spectrograph uses a
very compact design including a special triplet. It contains only spherical surfaces except for one tilted cylindrical
surface to disperse the light. To reduce the need for a high precision pointing, an Advanced Image Slicer was added in
front of the high resolution spectrograph. This spectrograph uses a simple design with only one mirror for the collimator
and another for the camera. The Imager contains dichroics to separate the bandwidths and glass thicknesses to
compensate the differences in path length. All 3 instruments use the same 2k x 2k detector simultaneously so that
telescope pointing and tip-tilt control of a fold mirror permit to place the gamma ray burst on the desired instrument
without any other mechanism.
OPTIMOS-EVE (OPTical Infrared Multi Object Spectrograph - Extreme Visual Explorer) is the fiber fed multi object
spectrograph proposed for the E-ELT. It is designed to provide a spectral resolution ranging from 5000 to 30.000, at
wavelengths from 0.37 μm to 1.70 μm, combined with a high multiplex (>200) and a large spectral coverage. The
system consists of three main modules: a fiber positioning system, fibers and a spectrograph.
The OPTIMOS-EVE Phase-A study, carried out within the framework of the ESO E-ELT instrumentation studies, has
been performed by an international consortium consisting of institutes from France, Netherlands, United Kingdom, Italy
and Denmark.
This paper describes the design tradeoff study and the key issues determining the price and performance of the
instrument.
OPTIMOS-EVE (OPTical Infrared Multi Object Spectrograph - Extreme Visual Explorer) is the fibre fed multi object
spectrograph proposed for the European Extremely Large Telescope (E-ELT), planned to be operational in 2018 at Cerro
Armazones (Chile). It is designed to provide a spectral resolution of 6000, 18000 or 30000, at wavelengths from 370 nm
to 1.7 μm, combined with a high multiplex (>200) and a large spectral coverage. Additionally medium and large IFUs
are available. The system consists of three main modules: a fibre positioning system, fibres and a spectrograph.
The recently finished OPTIMOS-EVE Phase-A study, carried out within the framework of the ESO E-ELT
instrumentation studies, has been performed by an international consortium consisting of institutes from France,
Netherlands, United Kingdom and Italy. All three main science themes of the E-ELT are covered by this instrument:
Planets and Stars; Stars and Galaxies; Galaxies and Cosmology.
This paper gives an overview of the OPTIMOS-EVE project, describing the science cases, top level requirements, the
overall technical concept and the project management approach. It includes a description of the consortium, highlights of
the science drivers and resulting science requirements, an overview of the instrument design and telescope interfaces, the
operational concept, expected performance, work breakdown and management structure for the construction of the
instrument, cost and schedule.
OCTOCAM is a multi-channel imager and spectrograph that has been proposed for the 10.4m GTC telescope. It will use
dichroics to split the incoming light to produce simultaneous observations in 8 different bands, ranging from the
ultraviolet to the near-infrared. The imaging mode will have a field of view of 2' x 2' in u, g, r, i, z, J, H and KS bands,
whereas the long-slit spectroscopic mode will cover the complete range from 4,000 to 23,000 A with a resolution of 700
- 1,000 (depending on the arm and slit width). An additional mode, using an image slicer, will deliver a spectral
resolution of over 3,000. As a further feature, it will use state of the art detectors to reach high readout speeds of the
order of tens of milliseconds. In this way, OCTOCAM will be occupying a region of the time resolution - spectral
resolution - spectral coverage diagram that is not covered by a single instrument in any other observatory, with an
exceptional sensitivity.
Waveguide image-slicer prototypes with resolutions up to 310.000 for the fiber fed PEPSI echelle spectrograph at the
LBT and single waveguide thicknesses of down to 30 μm have been manufactured. The waveguides were
macroscopically prepared, stacked up to an order of 7 and thinned back to square stack cross sections. A high filling ratio
was achieved by realizing homogenous adhesive gaps of 4.6 μm, using index matching adhesives for TIR within the
waveguides. The image-slicer stacks can be used in immersion mode and are miniaturized to be implemented in a set of
four, measurements indicate an overall efficiency of above 80% for them.
We investigate the potential of using adaptive optics (AO) in the V, R, and I bands to reach ultra-high resolution (UHR, R ≥ 200,000) in echelle spectrographs at 8-10m telescopes. In particular, we investigate the possibility of implementing an UHR mode for the fiber-fed spectrograph PEPSI (Potsdam Echelle Polarimetric and Spectrographic Instrument) being developed for the Large Binocular Telescope (LBT). By simulating the performances of the advanced AO system that will be available at first light at the LBT, and by using first-order estimates of the spectrograph performances, we calculate the total efficiency and signal to noise ratio (SNR) of PEPSI in the AO mode for stars of different magnitudes, different fiber core sizes, and different fractions of incident light diverted to the wavefront sensor. We conclude that AO can provide a significant advantage, of up to a factor ~2 in the V, R and I bands, for stars brighter than mR ~ 12 - 13. However, if these stars are observed at UHR in non-AO mode, slit losses caused by the need to use a very narrow slit can be compensated more effectively by the use of image slicers.
X-shooter is a single target spectrograph for the Cassegrain focus of one of the VLT UTs. It covers in a single exposure the spectral range from the UV to the H band with a possible extension into part of the K band. It is designed to maximize the sensitivity in this spectral range through the splitting in three arms with optimized optics, coatings, dispersive elements and detectors. It operates at intermediate resolutions (R=4000-14000, depending on wavelength and slit width) sufficient to address quantitatively a vast number of astrophysical applications while working in a background-limited S/N regime in the regions of the spectrum free from strong atmospheric emission and absorption lines. The small number of moving functions (and therefore instrument modes) and fixed spectral format make it easy to operate and permit a fast response. A mini-IFU unit (1.8" x 4") can be inserted in the telescope focal plane and is reformatted in a slit of 0.6"x 12" .The instrument includes atmospheric dispersion correctors in the UV and visual arms. The project foresees the development of a fully automatic data reduction package. The name of the instrument has been inspired by its capability to observe in a single shot a source of unknown flux distribution and redshift. The instrument is being built by a Consortium of Institutes from Denmark, France, Italy and the Netherlands in collaboration with ESO. When it operation, its observing capability will be unique at very large telescopes.
PEPSI is a high-resolution, fiber fed echelle spectrograph with polarimetric capabilities for the LBT. In order to reach a maximum resolution R=120.000 in polarimetric mode and 300.000 in integral light mode with high efficiency in the spectral range 390-1050~nm, we designed a white-pupil configuration with Maksutov collimators. Light is dispersed by an R4 31.6 lines/mm monolithic echelle grating mosaic and split into two arms through dichroics. The two arms, optimized for the spectral range 390-550~nm and 550-1050~nm, respectively, consist of Maksutov transfer collimators, VPH-grism cross dispersers, optimized dioptric cameras and 7.5K x 7.5K 8~μ CCDs. Fibers of different core sizes coupled to different image-slicers allow a high throughput, comparable to that of direct feed instruments. The optical configuration with only spherical and cylindrical surfaces, except for one aspherical surface in each camera, reduces costs and guarantees high optical quality. PEPSI is under construction at AIP with first light expected in 2006.
We describe the Nordic Optical Telescope's facility short- wavelength IR instrument, NOTCam. The instrument will be capable of wide-field and high-resolution imaging, long-slit and multi-object grism spectroscopy, coronography, and imaging-and spectro-polarimetry. First light will be in mid- 2000. Current progress is summarized and some problems we have encountered and overcome are discussed.
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