80 research outputs found
The E-ELT Multi-Object Spectrograph: latest news from MOSAIC
There are 8000 galaxies, including 1600 at z larger than 1.6, which could be
simultaneously observed in an E-ELT field of view of 40 sq. arcmin. A
considerable fraction of astrophysical discoveries require large statistical
samples, which can only be obtained with multi-object spectrographs (MOS).
MOSAIC will provide a vast discovery space, enabled by a multiplex of 200 and
spectral resolving powers of R=5000 and 20000. MOSAIC will also offer the
unique capability of more than 10 "high-definition" (multi-object adaptive
optics, MOAO) integral-field units, optimised to investigate the physics of the
sources of reionization. The combination of these modes will make MOSAIC the
world-leading MOS facility, contributing to all fields of contemporary
astronomy, from extra-solar planets, to the study of the halo of the Milky Way
and its satellites, and from resolved stellar populations in nearby galaxies
out to observations of the earliest "first-light" structures in the Universe.
It will also study the distribution of the dark and ordinary matter at all
scales and epochs of the Universe. Recent studies of critical technical issues
such as sky-background subtraction and MOAO have demonstrated that such a MOS
is feasible with state-of-the-art technology and techniques. Current studies of
the MOSAIC team include further trade-offs on the wavelength coverage, a
solution for compensating for the non-telecentric new design of the telescope,
and tests of the saturation of skylines especially in the near-IR bands. In the
2020s the E-ELT will become the world's largest optical/IR telescope, and we
argue that it has to be equipped as soon as possible with a MOS to provide the
most efficient, and likely the best way to follow-up on James Webb Space
Telescope (JWST) observations.Comment: 10 pages, 3 Figures, in Ground-based and Airborne Instrumentation for
Astronomy VI, 2016, Proc. SPI
EAGLE multi-object AO concept study for the E-ELT
EAGLE is the multi-object, spatially-resolved, near-IR spectrograph
instrument concept for the E-ELT, relying on a distributed Adaptive Optics,
so-called Multi Object Adaptive Optics. This paper presents the results of a
phase A study. Using 84x84 actuator deformable mirrors, the performed analysis
demonstrates that 6 laser guide stars and up to 5 natural guide stars of
magnitude R<17, picked-up in a 7.3' diameter patrol field of view, allow us to
obtain an overall performance in terms of Ensquared Energy of 35% in a 75x75
mas^2 spaxel at H band, whatever the target direction in the centred 5' science
field for median seeing conditions. The computed sky coverage at galactic
latitudes |b|~60 is close to 90%.Comment: 6 pages, to appear in the proceedings of the AO4ELT conference, held
in Paris, 22-26 June 200
Modélisation du comportement dynamique du prototype d’un concept de miroir déformable pour l’E-ELT
L’E-ELT est un projet d’extrêmement grand
télescope européen piloté par l’ESO dont la première lumière est attendue en 2017. Il
intègrera dans son schéma optique une optique adaptative équipée d’un miroir déformable
destinée à corriger les perturbations liées à la turbulence atmosphérique. Les
dimensions(diamètre et masse) élevées de ce miroir rendent incertaine l’absence
d’interactions entre le fonctionnementdu miroir et ses modes propres. L’étude
présente s’intéresse à la modélisation du prototype d’un concept de miroir déformable
proposé par l’industriel CILAS. L’accent est mis sur la base modale et sur les réponses
fréquentielles à des excitations de type inclinaison
Report drawn up on behalf of the Committee on Economic and Monetary Affairs on the proposal from the Commission of the European Communities to the Council (Doc. 1-99/83-COM(83) 85 final) for a Council Decision implementing the decision empowering the Commission to borrow under the New Community Instrument for the purpose of promoting investment within the Community, Working Documents 1983-1984, Document 1-236/83, 3 May 1983
The 4MOST([1]) 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 >25x10(6) 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 similar to 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 similar to 1600 targets at R similar to 5,000 from 390-900nm and similar to 800 targets at R>18,000 in three channels between similar to 395-675nm (channel bandwidth: 45nm blue, 57nm green and 69nm red) over a hexagonal field of view of similar to 4.1 degrees2. The initial 5-year 4MOST survey is currently expect to start in 2020. We provide and overview of the 4MOST systems: opto-mechanical, control, data management and operations concepts; and initial performance estimates
MOONS: a Multi-Object Optical and Near-infrared Spectrograph for the VLT
MOONS is a new conceptual design for a Multi-Object Optical and Near-infrared
Spectrograph for the Very Large Telescope (VLT), selected by ESO for a Phase A
study. The baseline design consists of 1000 fibers deployable over a field of
view of 500 square arcmin, the largest patrol field offered by the Nasmyth
focus at the VLT. The total wavelength coverage is 0.8um-1.8um and two
resolution modes: medium resolution and high resolution. In the medium
resolution mode (R=4,000-6,000) the entire wavelength range 0.8um-1.8um is
observed simultaneously, while the high resolution mode covers simultaneously
three selected spectral regions: one around the CaII triplet (at R=8,000) to
measure radial velocities, and two regions at R=20,000 one in the J-band and
one in the H-band, for detailed measurements of chemical abundances. The grasp
of the 8.2m Very Large Telescope (VLT) combined with the large multiplex and
wavelength coverage of MOONS - extending into the near-IR - will provide the
observational power necessary to study galaxy formation and evolution over the
entire history of the Universe, from our Milky Way, through the redshift desert
and up to the epoch of re-ionization at z>8-9. At the same time, the high
spectral resolution mode will allow astronomers to study chemical abundances of
stars in our Galaxy, in particular in the highly obscured regions of the Bulge,
and provide the necessary follow-up of the Gaia mission. Such characteristics
and versatility make MOONS the long-awaited workhorse near-IR MOS for the VLT,
which will perfectly complement optical spectroscopy performed by FLAMES and
VIMOS.Comment: 9 pages, 5 figures. To appear in the proceedings of the SPIE
Astronomical Instrumentation + Telescopes conference, Amsterdam, 201
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