R. Laureijs, R. Vavrek, G. Racca, R. Kohley, P. Ferruit, V. Pettorino, T. Bönke, A. Calvi, L. Gaspar Venancio, L. Campos, E. Maiorano, O. Piersanti, S. Prezelus, U. Ragnit, P. Rosato, C. Rosso, H. Rozemeijer, A. Short, P. Strada, D. Stramaccioni, M. Szafraniec, B. Altieri, G. Buenadicha, X. Dupac, P. Gómez Cambronero, K. Henares Vilaboa, C. Hernandez de la Torre, J. Hoar, M. Lopez-Caniego Alcarria, P. Marcos Arenal, J. Martin Fleitas, M. Miluzio, A. Mora, S. Nieto, R. Perez Bonilla, P. Teodoro Idiago, F. Cordero, J. Mendes, F. Renk, A. Rudolph, M. Schmidt, J. Schwartz, Y. Mellier, H. Aussel, M. Berthé, P. Casenove, M. Cropper, J. Cuillandre, J. Dinis, A. Gregorio, K. Kuijken, T. Maciaszek, L. Miller, R. Scaramella, M. Schirmer, I. Tereno, A. Zacchei, S. Awan, G. Candini, P. Liebing, R. Nakajima, S. Dusini, P. Battaglia, E. Medinaceli, C. Sirignano, I. Baldry, C. Baugh, F. Bernardeau, F. Castander, A. Cimatti, W. Gillard, L. Guzzo, H. Hoekstra, K. Jahnke, T. Kitching, E. Martin, J. Mohr, W. Percival, J. Rhodes
During its 6-year nominal mission, Euclid shall survey one third of the sky, enabling us to examine the spatial distributions of dark and luminous matter during the past 10 Gyr of cosmic history. The Euclid satellite was successfully launched on a SpaceX Falcon 9 launcher from Cape Canaveral on 1 July 2023 and is fully operational in a halo orbit around the Second Sun-Earth Lagrange point. We present an overview of the expected and unexpected findings during the early phases of the mission, in the context of technological heritage and lessons learnt. The first months of the mission were dedicated to the commissioning of the spacecraft, telescope and instruments, followed by a phase to verify the scientific performance and to carry out the in-orbit calibrations. We report that the key enabling scientific elements, the 1.2-meter telescope and the two scientific instruments, a visual imager (VIS) and a near-infrared spectrometer and photometer (NISP), show an inorbit performance in line with the expectations from ground tests. The scientific analysis of the observations from the Early Release Observations (ERO) program done before the start of the nominal mission showed sensitivities better than the prelaunch requirements. The nominal mission started in December 2023, and we allocated a 6-month early survey operations phase to closely monitor the performance of the sky survey. We conclude with an outlook of the activities for the remaining mission in the light of the in-orbit performance.
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.
Euclid, an ESA mission designed to characterise dark energy and dark matter, passed its Mission Critical Design Review in November 2018. It was demonstrated that the project is ready to start integration and test of the main systems, and that it has the ability to fulfil its top-level mission requirements. In addition, based on the performances at M-CDR, the scientific community has verified that the science requirements can be achieved for the Weak Lensing and Galaxy Clustering dark energy probes, namely a dark energy Figure of Merit of 400 and a 2% accuracy in the growth factor exponent gamma. We present the status of the main elements of the Euclid mission in the light of the demanding high optical performance which is the essential design driver is the to meet the scientific requirements. We include the space segment comprising of a service module and payload module hosting the telescope and its two scientific instruments, and the ground segment, which encompasses the operational and science ground segment. The elements for the scientific success of the mission for a timely release of the data are shortly presented: the processing and calibration of the data, and the design of the sky survey. Euclid is presently on schedule for a launch in September 2022.
Euclid-VIS is the large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled for launch in 2021. Together with the near infrared imaging within the NISP instrument, it forms the basis of the weak lensing measurements of Euclid. VIS will image in a single r+i+z band from 550-900 nm over a field of view of ~0.5 deg2 . By combining 4 exposures with a total of 2260 sec, VIS will reach to deeper than mAB=24.5 (10s) for sources with extent ~0.3 arcsec. The image sampling is 0.1 arcsec. VIS will provide deep imaging with a tightly controlled and stable point spread function (PSF) over a wide survey area of 15000 deg2 to measure the cosmic shear from nearly 1.5 billion galaxies to high levels of accuracy, from which the cosmological parameters will be measured. In addition, VIS will also provide a legacy dataset with an unprecedented combination of spatial resolution, depth and area covering most of the extra-Galactic sky. Here we will present the results of the study carried out by the Euclid Consortium during the period up to the beginning of the Flight Model programme
KEYWORDS: Space operations, Galactic astronomy, Spectroscopy, Systems modeling, Databases, Point spread functions, Seaborgium, Data processing, Calibration, Telescopes
ESA's Dark Energy Mission Euclid will map the 3D matter distribution in our Universe using two Dark Energy probes: Weak Lensing (WL) and Galaxy Clustering (GC). The extreme accuracy required for both probes can only be achieved by observing from space in order to limit all observational biases in the measurements of the tracer galaxies. Weak Lensing requires an extremely high precision measurement of galaxy shapes realised with the Visual Imager (VIS) as well as photometric redshift measurements using near-infrared photometry provided by the Near Infrared Spectrometer Photometer (NISP). Galaxy Clustering requires accurate redshifts (Δz/(z+1)<0.1%) of galaxies to be obtained by the NISP Spectrometer.
Performance requirements on spacecraft, telescope assembly, scientific instruments and the ground data-processing have been carefully budgeted to meet the demanding top level science requirements. As part of the mission development, the verification of scientific performances needs mission-level end-to-end analyses in which the Euclid systems are modeled from as-designed to final as-built flight configurations. We present the plan to carry out end-to-end analysis coordinated by the ESA project team with the collaboration of the Euclid Consortium. The plan includes the definition of key performance parameters and their process of verification, the input and output identification and the management of applicable mission configurations in the parameter database.
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).
KEYWORDS: Data processing, Galactic astronomy, Space operations, Telescopes, Point spread functions, K band, Sensors, Image quality, Data archive systems, Calibration
Euclid is a space-based optical/near-infrared survey mission of the European Space Agency (ESA) to investigate the
nature of dark energy, dark matter and gravity by observing the geometry of the Universe and on the formation of
structures over cosmological timescales. Euclid will use two probes of the signature of dark matter and energy: Weak
gravitational Lensing, which requires the measurement of the shape and photometric redshifts of distant galaxies, and
Galaxy Clustering, based on the measurement of the 3-dimensional distribution of galaxies through their spectroscopic
redshifts. The mission is scheduled for launch in 2020 and is designed for 6 years of nominal survey operations. The
Euclid Spacecraft is composed of a Service Module and a Payload Module. The Service Module comprises all the
conventional spacecraft subsystems, the instruments warm electronics units, the sun shield and the solar arrays. In
particular the Service Module provides the extremely challenging pointing accuracy required by the scientific objectives.
The Payload Module consists of a 1.2 m three-mirror Korsch type telescope and of two instruments, the visible imager
and the near-infrared spectro-photometer, both covering a large common field-of-view enabling to survey more than
35% of the entire sky. All sensor data are downlinked using K-band transmission and processed by a dedicated ground
segment for science data processing. The Euclid data and catalogues will be made available to the public at the ESA
Science Data Centre.
KEYWORDS: Point spread functions, Space operations, Galactic astronomy, Space telescopes, Charge-coupled devices, Calibration, Staring arrays, Sensors, Camera shutters, Radiation effects
Euclid-VIS is the large format visible imager for the ESA Euclid space mission in their Cosmic Vision program,
scheduled for launch in 2020. Together with the near infrared imaging within the NISP instrument, it forms the basis of
the weak lensing measurements of Euclid. VIS will image in a single r+i+z band from 550-900 nm over a field of view
of ~0.5 deg2. By combining 4 exposures with a total of 2260 sec, VIS will reach to deeper than mAB=24.5 (10σ) for
sources with extent ~0.3 arcsec. The image sampling is 0.1 arcsec. VIS will provide deep imaging with a tightly
controlled and stable point spread function (PSF) over a wide survey area of 15000 deg2 to measure the cosmic shear
from nearly 1.5 billion galaxies to high levels of accuracy, from which the cosmological parameters will be measured. In
addition, VIS will also provide a legacy dataset with an unprecedented combination of spatial resolution, depth and area
covering most of the extra-Galactic sky. Here we will present the results of the study carried out by the Euclid
Consortium during the period up to the Critical Design Review.
M. Siudek, K. Malek, B. Garilli, M. Scodeggio, A. Fritz, A. Pollo, U. Abbas, C. Adami, S. Arnouts, J. Bel, M. Bolzonella, D. Bottini, E. Branchini, A. Cappi, J. Coupon, O. Cucciati, I. Davidzon, G. De Lucia, S. de la Torre, P. Franzetti, M. Fumana, B. Granett, L. Guzzo, O. Ilbert, A. Iovino, J. Krywult, V. Le Brun, O. Le Fèvre, D. Maccagni, F. Marulli, H. McCracken, L. Paioro, M. Polletta, H. Schlagenhaufer, L. A. Tasca, R. Tojeiro, D. Vergani, A. Zanichelli, A. Burden, C. Di Porto, A. Marchetti, C. Marinoni, Y. Mellier, L. Moscardini, R. Nichol, J. Peacock, W. Percival, S. Phleps, M. Wolk, G. Zamorani
We present studies over the relations between stellar mass, redshift and star formation history for a high quality sample of early-type galaxies (ETGs) observed by the by the VIMOS Public Extragalactic Redshift Survey (VIPERS). VIPERS is an ongoing Large Programme to map in detail the large-scale distribution of galaxies at 0:5 < z < 1:2 with a unique volume (24 deg2) and sampling rate (~= 45%). At this redshift, IPERS fills a unique niche in galaxy surveys, provides a exceptional opportunity to study galaxies and their evolution at an epoch when the Universe had approximately half its current age. VIPERS data set will become the z ~ 1 equivalent of current state-of-the-art local (z < 0:2) surveys, allowing us to compare measurements at these two different epochs on equal statistical footing. The final sample of this survey is going to reach nearly 100,000 galaxies. As the VIPERS sample contains ~ 15% of the early type galaxies with known spectroscopic redshift and a very good quality spectra, it is a perfect sample to study the star formation history based on their spectroscopic features. We show that there the age of stellar population is depending on the stellar mass and the redshift. Our results show that lower mass galaxies have young stellar populations, while higher mass ETGs are populated with old stars. This suggest that marginal star formation occurs in massive galaxies. This result is consistent with the observations of the local Universe. Moreover, this trend of evolution is preserved for the different redshift range between 0:4 < z < 1:2.
In June 2012, Euclid, ESA's Cosmology mission was approved for implementation. Afterwards the industrial contracts were signed for the payload module and the spacecraft prime, and the mission requirements consolidated. We present the status of the mission in the light of the design solutions adopted by the contractors. The performances of the spacecraft in its operation, the telescope assembly, the scientific instruments as well as the data-processing have been carefully budgeted to meet the demanding scientific requirements. We give an overview of the system and where necessary the key items for the interfaces between the subsystems.
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.
Euclid-VIS is the large format visible imager for the ESA Euclid space mission in their Cosmic Vision program,
scheduled for launch in 2020. Together with the near infrared imaging within the NISP instrument, it forms the basis of
the weak lensing measurements of Euclid. VIS will image in a single r+i+z band from 550-900 nm over a field of view
of ~0.5 deg2. By combining 4 exposures with a total of 2260 sec, VIS will reach to V=24.5 (10σ) for sources with extent
~0.3 arcsec. The image sampling is 0.1 arcsec. VIS will provide deep imaging with a tightly controlled and stable point
spread function (PSF) over a wide survey area of 15000 deg2 to measure the cosmic shear from nearly 1.5 billion
galaxies to high levels of accuracy, from which the cosmological parameters will be measured. In addition, VIS will also
provide a legacy dataset with an unprecedented combination of spatial resolution, depth and area covering most of the
extra-Galactic sky. Here we will present the results of the study carried out by the Euclid Consortium during the period
up to the Preliminary Design Review.
C. Evans, M. Puech, B. Barbuy, P. Bonifacio, J.-G. Cuby, E. Guenther, F. Hammer, P. Jagourel, L. Kaper, S. Morris, J. Afonso, P. Amram, H. Aussel, A. Basden, N. Bastian, G. Battaglia, B. Biller, N. Bouché, E. Caffau, S. Charlot, Y. Clénet, F. Combes, C. Conselice, T. Contini, G. Dalton, B. Davies, K. Disseau, J. Dunlop, F. Fiore, H. Flores, T. Fusco, D. Gadotti, A. Gallazzi, E. Giallongo, T. Gonçalves, D. Gratadour, V. Hill, M. Huertas-Company, R. Ibata, S. Larsen, O. Le Fèvre, B. Lemasle, C. Maraston, S. Mei, Y. Mellier, G. Östlin, T. Paumard, R. Pello, L. Pentericci, P. Petitjean, M. Roth, D. Rouan, D. Schaerer, E. Telles, S. Trager, N. Welikala, S. Zibetti, B. Ziegler
Over the past 18 months we have revisited the science requirements for a multi-object spectrograph (MOS) for the
European Extremely Large Telescope (E-ELT). These efforts span the full range of E-ELT science and include input
from a broad cross-section of astronomers across the ESO partner countries. In this contribution we summarise the key
cases relating to studies of high-redshift galaxies, galaxy evolution, and stellar populations, with a more expansive
presentation of a new case relating to detection of exoplanets in stellar clusters. A general requirement is the need for
two observational modes to best exploit the large (≥40 arcmin2) patrol field of the E-ELT. The first mode (‘high
multiplex’) requires integrated-light (or coarsely resolved) optical/near-IR spectroscopy of >100 objects simultaneously.
The second (‘high definition’), enabled by wide-field adaptive optics, requires spatially-resolved, near-IR of >10
objects/sub-fields. Within the context of the conceptual study for an ELT-MOS called MOSAIC, we summarise the toplevel
requirements from each case and introduce the next steps in the design process.
Jean-Charles Cuillandre, Kanoa Withington, Patrick Hudelot, Yuliana Goranova, Henry McCracken, Frédéric Magnard, Yannick Mellier, Nicolas Regnault, Marc Bétoule, Hervé Aussel, J. J. Kavelaars, Pierre Fernique, François Bonnarel, Francois Ochsenbein, Olivier Ilbert
The Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) is a high impact scientific program which will
see its final official release open to the world in 2012. That release will seal the legacy aspect of the survey
which has already produced a large collection of scientific articles with topics ranging from cosmology to the
Solar system. The survey core science was focused on dark energy and dark matter: the full realization of the
scientific potential of the data set gathered between 2003 and 2009 with the MegaCam wide-field imager mounted
at the CFHT prime focus is almost complete with the Supernovae Legacy Survey (SNLS) team preparing its
third and last release (SNLS5), and the CFHTLenS team planning the release based around the cosmic shear
survey later this year. While the data processing center TERAPIX offered to the CFHTLS scientific community
regular releases over the course of the survey in its data acquisition phase (T0001-T0006), the final release took
three years to refine in order to produce a pristine data collection photometrically calibrated at better than the
percent both internally and externally over the total survey surface of 155 square degrees in all five photometric
bands (u*, g’, r’, i’, z’). This final release, called T0007, benefits from the various advances in photometric
calibration MegaCam has benefited through the joint effort between SNLS and CFHT to calibrate MegaCam
at levels unexplored for an optical wide-field imager. T0007 stacks and catalogs produced by TERAPIX will be
made available to the world at CADC while the CDS will offer a full integration of the release in its VO tools
from VizieR to Aladin. The photometric redshifts have been produced to be released in phase with the survey.
This proceeding is a general introduction to the survey and aims at presenting its final release in broad terms.
Euclid is a space-borne survey mission developed and operated by ESA. It is designed to understand the origin of the
Universe's accelerating expansion. Euclid will use cosmological probes to investigate the nature of dark energy, dark
matter and gravity by tracking their observational signatures on the geometry of the Universe and on the history of
structure formation. The mission is optimised for the measurement of two independent cosmological probes: weak
gravitational lensing and galaxy clustering. The payload consists of a 1.2 m Korsch telescope designed to provide a large
field of view. The light is directed to two instruments provided by the Euclid Consortium: a visual imager (VIS) and a
near-infrared spectrometer-photometer (NISP). Both instruments cover a large common field of view of 0.54 deg2, to be
able to survey at least 15,000 deg2 for a nominal mission of 6 years. An overview of the mission will be presented: the
scientific objectives, payload, satellite, and science operations. We report on the status of the Euclid mission with a
foreseen launch in 2019.
The Euclid mission objective is to map the geometry of the dark Universe by investigating the distance-redshift
relationship and the evolution of cosmic structures. The NISP (Near Infrared Spectro-Photometer) is one of the two
Euclid instruments operating in the near-IR spectral region (0.9-2μm). The instrument is composed of:
- a cold (140K) optomechanical subsystem constituted by a SiC structure, an optical assembly, a filter wheel
mechanism, a grism wheel mechanism, a calibration unit and a thermal control
- a detection subsystem based on a mosaic of 16 Teledyne HAWAII2RG 2.4μm. 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.
This presentation will describe the architecture of the instrument, the expected performance and the technological key
challenges. This paper is presented on behalf of the Euclid Consortium.
J. Amiaux, R. Scaramella, Y. Mellier, B. Altieri, C. Burigana, Antonio Da Silva, P. Gomez, J. Hoar, R. Laureijs, E. Maiorano, D. Magalhães Oliveira, F. Renk, G. Saavedra Criado, I. Tereno, J. Auguères, J. Brinchmann, M. Cropper, L. Duvet, A. Ealet, P. Franzetti, B. Garilli, P. Gondoin, L. Guzzo, H. Hoekstra, R. Holmes, K. Jahnke, T. Kitching, M. Meneghetti, W. Percival, S. Warren
KEYWORDS: Calibration, Space operations, Galactic astronomy, Near infrared, Visible radiation, Photometry, Point spread functions, Signal to noise ratio, Stars, Near infrared spectroscopy
Euclid is an ESA Cosmic-Vision wide-field-space mission which is designed to explain the origin of the acceleration of
Universe expansion. The mission will investigate at the same time two primary cosmological probes: Weak gravitational
Lensing (WL) and Galaxy Clustering (in particular Baryon Acoustic Oscillations, BAO). The extreme precision
requested on primary science objectives can only be achieved by observing a large number of galaxies distributed over
the whole sky in order to probe the distribution of dark matter and galaxies at all scales. The extreme accuracy needed
requires observation from space to limit all observational biases in the measurements. The definition of the Euclid
survey, aiming at detecting billions of galaxies over 15 000 square degrees of the extragalactic sky, is a key parameter of
the mission. It drives its scientific potential, its duration and the mass of the spacecraft. The construction of a Reference
Survey derives from the high level science requirements for a Wide and a Deep survey. The definition of a main
sequence of observations and the associated calibrations were indeed a major achievement of the Definition Phase.
Implementation of this sequence demonstrated the feasibility of covering the requested area in less than 6 years while
taking into account the overheads of space segment observing and maneuvering sequence. This reference mission will be
used for sizing the spacecraft consumables needed for primary science. It will also set the framework for optimizing the
time on the sky to fulfill the primary science and maximize the Euclid legacy.
KEYWORDS: Image compression, Charge-coupled devices, Data compression, Interfaces, Data processing, Electronics, Imaging systems, Image processing, Detection and tracking algorithms, Control systems
The Command and Data Processing Unit (CDPU) of the Euclid Visible Imager is one of the two warm electronics units
of the instrument. It implements on one side the digital interface to the satellite, for telecommands acquisition and
telemetry downloading, and on the other side the interface to the focal plane CCDs readout electronics, for science data
acquisition and compression. The CDPU main functionalities include the instrument commanding, control and health
monitoring. The baseline unit architecture is presented, reporting the results of the phase B1 study and of the trade-off
activity carried out to check the performances of the SW implementation of two different lossless compression
algorithms on the baseline target processor (LEON3-FT) and on a HW compressor.
KEYWORDS: Charge-coupled devices, Calibration, Point spread functions, Galactic astronomy, Sensors, Staring arrays, Camera shutters, Space operations, Radiation effects, Imaging systems
Euclid-VIS is a large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled
for launch in 2019. Together with the near infrared imaging within the NISP instrument it forms the basis of the weak
lensing measurements of Euclid. VIS will image in a single r+i+z band from 550-900 nm over a field of view of ~0.5
deg2. By combining 4 exposures with a total of 2240 sec, VIS will reach to V=24.5 (10σ) for sources with extent ~0.3
arcsec. The image sampling is 0.1 arcsec. VIS will provide deep imaging with a tightly controlled and stable point spread
function (PSF) over a wide survey area of 15000 deg2 to measure the cosmic shear from nearly 1.5 billion galaxies to
high levels of accuracy, from which the cosmological parameters will be measured. In addition, VIS will also provide a
legacy imaging dataset with an unprecedented combination of spatial resolution, depth and area covering most of the
extra-Galactic sky. Here we will present the results of the study carried out by the Euclid Consortium during the Euclid
Definition phase.
The 'Imaka project is a high-resolution wide-field imager proposed for the Canada-France-Hawaii telescope
(CFHT) on Mauna Kea. 'Imaka takes advantage of two features of the optical turbulence above Mauna Kea:
weak optical turbulence in the free-atmosphere and boundary layer turbulence which is highly confined within a
surface layer tens of meters thick and or the telescope enclosures. The combination of the two allows a groundlayer
adaptive optics system (GLAO) to routinely deliver an extremely-wide corrected field of view of one-degree
at an excellent free-atmosphere seeing limit at visible wavelengths. In addition, populating the focal-plane with
orthogonal-transfer CCDs provides a second level of image improvement on the free-atmosphere seeing and the
residual GLAO correction. The impact of such an instrument covers a broad range of science and is a natural
progression of CFHT's wide-field expertise.
The goal of this project is to achieve exquisite image quality over the largest possible field of view, with a goal of a
FWHM of not more than 0.3" over a square degree field in the optical domain. The narrow PSF will allow detection of
fainter sources in reasonable exposure times. The characteristics of the turbulence of Mauna Kea, a very thin ground
layer with excellent free seeing allows very wide fields to be corrected by GLAO and would make such an instrument
unique. The Ground Layer AO module uses a deformable mirror conjugated to the telescope pupil. Coupled with a high
order WFS, it corrects the turbulence common to the entire field. Over such large fields the probability of finding
sufficiently numerous and bright natural guide sources is high, but a constellation of laser beacons could be considered
to ensure homogeneous and uniform image quality.
The free atmosphere seeing then limits the image quality (50% best conditions: 0.2" to 0.4"). This can be further
improved by an OTCCD camera, which can correct local image motion on isokinetic scales from residual high altitude
tip-tilt. The advantages of the OTCCD are not limited to improving the image quality: a Panstarrs1 clone covers one
square degree with 0.1" sampling, in perfect accordance with the scientific requirements. The fast read time (6 seconds
for 1.4 Gpixels) also leads to an improvement of the dynamic range of the images. Finally, the guiding capabilities of
the OTCCD will provide the overall (local and global) tip-tilt signal.
Alicia Berciano Alba, Pedro Borges de Silva, Hans Eichelberger, Francesca Giovacchini, Mareike Godolt, Günther Hasinger, Michael Lerchster, Vincent Lusset, Fabio Mattana, Yannick Mellier, Michal Michalowski, Carlos Monteserin-Sanchez, Fabio Noviello, Carina Persson, Andrea Santovincenzo, Peter Schneider, Ming Zhang, Linda Östman
We outline a novel satellite mission concept, DEMON, aimed at
advancing our comprehension of both dark matter and dark energy, taking full advantage of two complementary methods: weak lensing and
the statistics of galaxy clusters. We intend to carry out a 5000 deg2 combined IR, optical and X-ray survey with galaxies up to a redshift of z~2 in order to determine the shear correlation
function. We will also find ~100000 galaxy clusters, making it
the largest survey of this type to date. The DEMON spacecraft will
comprise one IR/optical and eight X-ray telescopes, coupled to
multiple cameras operating at different frequency bands. To a great
extent, the technology employed has already been partially tested on
ongoing missions, therefore ensuring improved reliability.
Understanding the nature of Dark Matter and Dark Energy is one of the most pressing issues in cosmology
and fundamental physics. The purpose of the DUNE (Dark UNiverse Explorer) mission is to study these two
cosmological components with high precision, using a space-based weak lensing survey as its primary science
driver. Weak lensing provides a measure of the distribution of dark matter in the universe and of the impact
of dark energy on the growth of structures. DUNE will also include a complementary supernovae survey to
measure the expansion history of the universe, thus giving independent additional constraints on dark energy.
The baseline concept consists of a 1.2m telescope with a 0.5 square degree optical CCD camera. It is designed
to be fast with reduced risks and costs, and to take advantage of the synergy between ground-based and space
observations. Stringent requirements for weak lensing systematics were shown to be achievable with the baseline
concept. This will allow DUNE to place strong constraints on cosmological parameters, including the equation
of state parameter of the dark energy and its evolution from redshift 0 to 1. DUNE is the subject of an ongoing
study led by the French Space Agency (CNES), and is being proposed for ESA's Cosmic Vision programme.
PRIME (The Primordial Explorer) is a proposed Explorer-class mission. It will carry out a deep sky survey from space in four near-infrared bands between ~0.9-3.5 μm. It surveys a quarter of the sky to AB magnitude of ~24, which is ~600 times deeper than 2MASS and ~ five million times deeper than COBE at long wavelengths. Deeper surveys in selected sky regions are also planned. PRIME will reach an epoch during which the first quasars, galaxies and clusters of galaxies were formed in the early universe, map the large-scale structure of the dark matter, discover Type-Ia supernovae to be used in measuring the acceleration of the expanding universe, and detect thousands of brown dwarfs and even Jupiter-size planets in the vicinity of the solar system. Most of these objects are so rare that they may be identified only in large and deep surveys. PRIME will serve as the precursor for the Next Generation Space Telescope (NGST), supplying rare targets for its spectroscopy and deep imaging. It is more than capable of providing targets for the largest ground-based telescopes (10-30m). Combining PRIME with other surveys (SDSS, GALEX) will yield the largest astronomical database ever built.
KEYWORDS: Galactic astronomy, Galaxy groups and clusters, Telescopes, Distortion, Near infrared, Signal to noise ratio, Statistical analysis, Data modeling, Image quality, Large telescopes
The present status of weak lensing analyses of clusters of galaxies and of cosmic shear surveys are presented and discussed. We focus on the impact of very large telescopes on present-day and future surveys and compare their potential with HST or wide field 4 meter telescopes.
Oliver Le Fevre, Gianpaolo Vettolani, Dario Maccagni, D. Mancini, Alain Mazure, Yannick Mellier, Jean Picat, M. Arnaboldi, S. Bardelli, E. Bertin, G. Busarello, A. Cappi, S. Charlot, Guido Chincarini, S. Colombi, M. Dantel-Fort, S. Foucaud, Bianca Garilli, Luigi Guzzo, A. Iovino, C. Marinoni, G. Mathez, Henry McCracken, Roser Pello, Mario Radovich, V. Ripepi, P. Saracco, Roberto Scaramella, M. Scoreggio, Laurence Tresse, Alessandro Zanichelli, G. Zamorani, E. Zucca
The Virmos-VLT deep survey (VVDS) is aimed to study the evolution of galaxies, large scale structure and AGNs over more than 90% of the current age of the Universe, based on a large number (more than 100.000) of spectra of galaxies. In a first step, the Vimos Spectrograph will be used to measure all galaxies from magnitude limited samples. In a second step, near IR spectroscopy will be obtained with the Nirmos spectrograph, to measure redshifts in the critical range 1.2AB = 22.5. At the center of one region a deep survey will be conducted for galaxies brighter than IAB = 24. This deep region has also been imaged at the VLA (1400 MHz) to a flux limit of 0.08 mJy and is being observed in X-Rays with XMM.
We present the current status of cosmic shear based on all surveys done so far. Taken together, they cover more about 70 deg2 and concern more than 3 million galaxies with accurate shape measurement. Theoretical expectations, observational results and their cosmological interpretations are discussed in the framework of standard cosmology and CDM scenarios. The potentials of the next generation cosmic shear surveys are discussed.
KEYWORDS: Observatories, Astronomy, Standards development, Data centers, Data storage, Data archive systems, Astronomical imaging, Prototyping, Web services, Astronomical telescopes
The Astrophysical Virtual Observatory Project (AVO: http://www.eso.org/projects/avo/) will conduct a research and demonstration program on the scientific requirements and technologies necessary to build a VO for European astronomy. The AVO has been jointly funded by the European Commission and six European organizations for a three year Phase-A work program valued at 5 million Euro. The Phase A program will focus its work in three areas -- science requirements, archive interoperability and GIRD/database technologies. The AVO project, the US NVO and UK ASTROGRID projects have been working closely together over the past nine months to reach consensus on essential technical directions and standards that will facilitate the possibility of an International Virtual Observatory. An International Virtual Observatory Alliance was formed in June 2002 among all currently funded and proposed VO projects. The IVOA has adopted a roadmap for IVO developments over the next three years that will feature coordinated demonstrations of VO capabilities on specific science programs, and international agreements on key interoperability standards and tools.
The VIRMOS consortium of French and Italian Institutes is manufacturing 2 wide field imaging multi-object spectrographs for the European Southern Observatory Very Large Telescope, with emphasis on the ability to carry over spectroscopic surveys of large numbers of sources. The Visible Multi-Object Spectrograph, VIMOS, is covering the 0.37 to 1 micron wavelength domain, with a full field of view of 4 by 7 by 8 arcmin2 in imaging and MOS mode. The Near IR Multi-Object Spectrograph, NIRMOS, is covering the 0.9 to 1.8 microns wavelength range, with afield of view 4 by 6 by 8 arcmin2 in MOS mode. The spectral resolution for both instrument scan reach up to R equals 5000 for a 0.5 arcsec wide slit. Multi-slit masks are produced by a dedicated Mask Manufacturing Machine cutting through thin Invar sheets and capable of producing 4 slit masks approximately 300 by 300 mm each with approximately slits 5.7 mm long in less than one hour. Integral field spectroscopy is made possible in VIMOS by switching in the beam specially build masks fed by 6400 fibers coming form a 54 by 54 arcsec2 integral field head with a 80 by 80 array of silica micro-lenses. NIRMOS has a similar IFS unit with a field of 30 by 30 arcmin2. These instruments are designed to offer very large multiplexing capabilities. In MOS mode, about 1000 objects can be observed simultaneously with VIMOS, with a S/N equals 10 obtained on galaxies with I equals 24 in one hour, and approximately 200 objects can be observed simultaneously with NIRMOS, with a S/N equals 10 obtained don galaxies with J equals 22, H equals 20.6 in 1h at Req equals 200. We present here the status of VIMOS, currently under final integration, with expected first light in the summer 2000, together with the final design of NIRMOS presented at the Final Design Review. The VLT-VIRMOS deep redshift survey of more with the final design of NIRMOS presented at the Final Design Review. The VLT-VIRMOS deep redshift survey of more than 150000 galaxies over the redshift range 0 < z < 5 will be undertaken based on 120 guaranteed nights awarded to the project.
Olivier Boulade, Xavier Charlot, P. Abbon, Stephan Aune, Pierre Borgeaud, Pierre-Henri Carton, M. Carty, D. Desforge, Dominique Eppele, Pascal Gallais, L. Gosset, Remy Granelli, Michel Gros, Jean de Kat, Denis Loiseau, Yannick Mellier, J. Ritou, Jean Rousse, Pierre Starzynski, Nicolas Vignal, Laurent Vigroux
MegaCam is the new wide-field imaging camera currently being built for the new prime focus of the 3.6m Canada-France- Hawaii Telescope. The camera will offer a 1 square degree field of view and is built around a mosaic of 40 2K by 4.5K CCD devices. The delivery of the CCDs is proceeding along the schedule, the project passe dits final design review and the realization phase started, for an expected delivery to CFHT in Summer 2001.
We present the current design of the VIsible Multi-Object Spectrograph (VIMOS) and the Near InfraRed Multi-Object Spectrograph (NIRMOS) for the European Southern Observatory Very Large Telescope. The basic scientific requirement is to conduct very deep redshift surveys of large quantities of objects, in a minimum number of nights. The technical specifications are to allow for a large multiplex gain over a wide field, and a high efficiency of the optical train, over the 0.37 to 1.8 micrometer domain. The baseline technical concept is built around 4 channels, covering 4 X 7 X 8 arcmin2 for VIMOS and 4 X 7 X 7 arcmin2 for NIRMOS. Each channel is an imaging spectrograph with a large field adaptation lens, a collimator, grisms or filters, and a F/1.8 camera, coupled to a 2048 X 4096 pixels CCD for VIMOS, and a 20482 HgCdTe Rockwell array for NIRMOS. The unique multiplex gain allows to obtain spectra of up to 840 object simultaneously with VIMOS, and up to 170 with NIRMOS (10 arcsec slits). An integral field spectroscopy mode with more than 6400 fibers coupled to micro-lenses will be available for VIMOS, covering a 1 X 1 arcmin2 field. The VLT-VIRMOS survey of more than 150,000 galaxies is planned down to magnitudes IAB equals 24, coupled to an ultra deep probe to IAB equals 26.
Olivier Boulade, Laurent Vigroux, Xavier Charlot, Pierre Borgeaud, Pierre-Henri Carton, Jean de Kat, Jean Rousse, Yannick Mellier, Pierre Gigan, David Crampton, Christopher Morbey
KEYWORDS: Charge-coupled devices, Cameras, Telescopes, Control systems, Electronics, CCD cameras, Digital signal processing, Imaging systems, Camera shutters, Power supplies
MEGACAM is the next generation wide-field camera to be used at the prime focus of the 3.6 m CFHT telescope. This instrument, which will cover a full 1 square degree, is designed around a mosaic of 36 to 40 2K X 4K CCDs. such a large detector requires new approaches for the hardware as well as the software, and will have major impacts on the telescope structure, optics and operations. We present in this paper several novel ideas and techniques that will be implemented as part of this challenging project.
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