The Mid-Infrared Imager/Spectrometer/Coronagraph instrument (MISC) is one of the five focal plane instruments studied for the Origins Space Telescope. The MISC instrument will observe at the shortest wavelengths of any of these instruments, ranging from 5 to 38 microns. The MISC instrument consists of three modules including the MISC Imager and Spectrometer (MISC I&S) module, the MISC Coronagraph (MISC COR) module, and the MISC Transit spectrometer (MISC TRA) module.
The MISC I&S module offers (1) a wide field imaging (3 arcmin x 3 arcmin) and low-resolution spectroscopic capability with filters and grisms for 6-38 microns, (2) a medium-resolution (R~1,000) Integral Field Unit (IFU) spectroscopic capability for 5-38 microns, and (3) a high-resolution (R~25,000) slit spectroscopic capability for 12-18 and 25-36 microns. The diffraction-limited image quality is achieved at any wavelength in 6-38 microns with the help of a deformable mirror and a tip tilt mirror in the fore optics of the MISC I&S module. The MISC I&S imager also provides the OST a focal plane guiding function for the other OST science instruments as well as its own use. The MISC COR module employs the PIAA coronagraphy method and covers 6-38 microns, achieving 10-7 contrast at 0.5” from the central star. An deformable mirror and a tip tilt mirror are also equipped in the fore optics of MISC COR to correct for the wave front errors in the telescope beam. The MISC TRA module employs a densified pupil spectroscopic design and covers 5-26µm with R~100–300 while achieving 3-5ppm of spectro-photometric stability.
The MISC I&S module will provide OST with crucial capabilities for various science cases, e.g., to study episodic accretion in protostellar envelopes, to trace the rise in metallacity and dust over cosmic time (when combined with far-infrared measurements), to measure dust in galactic outflows, to assess feedback from supernovae and AGN on the multi-phase ISM in galaxies, and to characterize the AGN and starburst power in normal and massive galaxies. The highest ever spectro-photometric stability achieved by MISC TRA module as well as the high-contrast coronagraphic imaging and spectroscopic capability at small inner working angles from the central bright source achieved by MISC COR module will make the OST a powerful tool to bring revolutionary progress in exoplanet sciences through the detection of exoplanet atmospheric biosignatures and the direct imaging of Jovian planets orbiting older stars at separations of 5-20 AU.
This paper, “The micro-mirror technology applied to astronomy: ANIS adaptive-slit near Infrared spectrograph," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.
Based on the micro-electronics fabrication process, MicroOpto-Electro-Mechanical Systems (MOEMS) are under study, in order to be integrated in next-generation astronomical instruments and telescopes, especially for space missions. The main advantages of micro-optical components are their compactness, scalability, specific task customization using elementary building blocks, and they allows remote control. As these systems are easily replicable, the price of the components is decreasing dramatically when their number is increasing. The two major applications of MOEMS are Multi-Object Spectroscopy masks and Deformable Mirror systems.
FLARE (First Light And Reionization Explorer) is a space mission that will be submitted to ESA (M5 call). Its primary goal (~80% of lifetime) is to identify and study the universe before the end of the reionization at z > 6. A secondary objective (~20% of lifetime) is to survey star formation in the Milky Way.
FLARE's strategy optimizes the science return: imaging and spectroscopic integral-field observations will be carried out simultaneously on two parallel focal planes and over very wide instantaneous fields of view.
FLARE will help addressing two of ESA’s Cosmic Vision themes: a) << How did the universe originate and what is it made of? » and b) « What are the conditions for planet formation and the emergence of life? >> and more specifically, << From gas and dust to stars and planets >>.
FLARE will provide to the ESA community a leading position to statistically study the early universe after JWST’s deep but pin-hole surveys. Moreover, the instrumental development of wide-field imaging and wide-field integral-field spectroscopy in space will be a major breakthrough after making them available on ground-based telescopes.
Ground-layer adaptive optics (GLAO) has the potential to dramatically increase the efficiency and capabilities of
existing ground-based telescopes over a broad range of astronomical science. Recent studies of the optical turbulence
above several astronomical sites (e.g. Mauna Kea, Paranal, and Antarctica) show that GLAO can be extended to fields of
view of several tens of arcminutes in diameter, larger than previously thought, with angular resolutions close to the freeatmosphere
seeing. This is a pivotal result since GLAO science cases benefit from the largest possible corrected fields
of view. The corrected areal field of a GLAO system is potentially 2-3 orders of magnitude larger than has been
demonstrated to date. The 'Imaka team is working toward an instrument that takes advantage of the one-degree field
afforded by Mauna Kea. In this paper we summarize the design/simulation work to date along with our plan to develop
an instrument that reaches for this wide field of view.
At Dome C, Antarctica, the whole turbulence is reduced to a boundary layer of about 50 meters. WHITE is a project of an infrared survey based on a 2-m telescope using a ground-layer adaptive-optics instrument to obtain high angular resolution on a wide field of view. Simulation results obtained both analytically and from a numerical end-to-end approach are presented and then compared.
What is a good astronomical site? It must be cold, dry, stable, dark. There is one site on Earth that qualifies : Antarctica.
To make the best use of these characteristics, we propose a
Wide-field (0.5-degree in diameter) High-resolution (~0.3
arcsec using GLAO from the ice), IR (0.8-5 μm) 2.4-m TElescope (WHITE). WHITE will be dedicated to carrying out
surveys: a deep extragalactic field over a few square degrees, a survey of the Magellanic Clouds. By adding one more
year, WHITE would be able to add one kilo-degree survey.
In May 2000, the Canada-France-Hawaii (CFHT) Telescope Science Advisory Committee solicited the Canadian, Hawaiian and French communities to propose concepts to replace the present CFH telescope by a larger telescope. Three groups were selected: Carlberg et al. (2001) in Canada, Khun et al. (2001) in Hawaii and Burgarella et al. (2001a) in France. The reports were delivered to CFHT in May 2001 and are now available throughout the CFHT website. One of the main constraints was due to the fact that the new and larger telescope should use as much as possible the existing site and be compliant with the Mauna Kea Science reserve Master Plan (2000). This plan analyses all aspects of the Mauna Kea summit but most of them are related to the facts that the mountain must be considered as a sacred area for indigenous Hawaiian people and that the ecosystem is fragile. But in addition, the plan also tries to account for the fact that the summit of Mauna Kea is a world famous site for astronomy. The points that we can highlight in the context of our project are of two types. Since then, the project evolved and Hawaii is not considered as the one and only site to build an Extremely Large Telescope (ELT). Moreover, the size of the primary mirror, which was strongly dependent on the above constraints, is no more limited to the 16 - 20 m which was our conclusion at this time. Nevertheless, the three points of the resolution are still valid and since then, we have kept on working on the concept by launching differnt follow-up studies that are necessary to start such a project. Of course, the main point is the Science Objectives which drive the main specifications for an ELT. But related technical studies are also mandatory e.g. Adaptive Optics, Building of a primary mirror larger than 30 m in diameter, Image Quality as a function of the segment size and shape.
In this paper, we show that the determination of the morphological type could be difficult when we observe galaxies in the rest-frame ultraviolet. This could be crucial as soon as we wish to study galaxies at redshifts beyond z~1 since the visible wavelength range corresponds to the rest-frame ultraviolet. In order to address the problem of performing a morphological analysis on a large number of galaxies as the very large samples that will be secured by GALEX, SLOAN, ASTRO-F in the near- to mid-term and from NGST, ALMA and ELT's later on, we need to define a simple quantitative and automatic method. We propose a quantitative multi-wavelength classification that would take into account the various stellar populations lying in the observed galaxies. This method makes use of multi-wavelength data but such databases are already needed to estimate the distance through photometric redshifts. SpectroMorphology allows to perform an automatic analysis of the nature of galaxies.
Considered until recently one of the best telescopes in the world, the Canada-France-Hawaii Telescope (CFHT) is now bypassed by larger telescopes. Aware of this problem, the CFHT Science Advisory Council (SAC) solicited proposals from the CFH community groups to replace the present telescope by a world-class research facility before the end of the decade. A report describing our proposal is available on our web site (www.astrsp-mrs.fr/denis/ngcfht/ngcfht.html). The motivation to design and build a new telescope is often driven by the astronomers need to observe fainter and fainter sources. The basis of the next generation CFHT (NG-CFHT) is therefore to increase the size of the primary mirror to reach fainter and more remote objects in the luminosity functions. But beyond this photon quest , the way we use the photons is also very important. The development of new technologies will permit an optimization of performances and a better image quality thanks to state-of-the-art instruments on state-of-the-art telescopes.
A Multi-Object Spectrograph (MOS) based on micro-opto- electro-mechanical systems is one of the three core instruments selected for the NGST. Our group is involved in the preliminary studies on a promising solution for this instrument using a Micro-Mirror Array (MMA). We have focused our work towards three main topics: surface characterization of the micro-mirrors, MMA optical modeling, and optical design for the MOS. An accurate surface characterization method, based upon Foucault's knife-edge test has been developed, for measuring sub-nanometer deformations. Using the non-sequential ray tracing ability of our ray-tracing program, we have simulated a block of nine micro-mirrors with individual tilt angles, for properly designing an MMA- MOS. Finally, two different concepts for the MOS have been studied: a spectrograph with focal reduction, and a unit- magnification spectrograph preceded by a focal adaptator. The unit-magnification all-reflecting spectrograph is very promising, with a compact design, a perfectly plane image surface, and geometrical spots smaller than the detector pixels.
Development of accurate surface characterization methods is essential for testing micro-optical components, such as micro- opto-electro-mechanical systems (MOEMS), for use in complex optical systems. We consider using an array of 16 micrometer- wide micro-mirrors as programmable slits for astronomical multi-object spectroscopy, and propose a new method based upon Foucault's knife-edge test to characterize local surface deformations of individual micro-mirrors. By measuring local slopes, the surface shape of each mirror in a micro-mirror array has been reconstructed with a sub-nanometer accuracy. In addition to low-order deformation (tilt, curvature, astigmatism), each mirror is seen to be palm-tree shaped. We have checked the validity of our knife-edge test by the micro- characterization of a conventional spherical mirror.
This paper analyses the various ways of carrying out near IR multi-object spectroscopic studies in space. We show that ground-based observations would have limited results except in the 1-1.5 micrometers wavelength where large telescope of the 8m class would be approximately equivalent to a 1m in space. Beyond 2m, even an instrument such as the adaptive-slit near IR (ANIS) would be much more efficient. Due to their position in space, the traditional masks used in ground- based telescopes cannon be used. New technologies must be developed. Here, we present a multi-object spectrograph called ANIS based on micro-mirror arrays and designed for NGST PathFinder3. It would be able to perform a near IR spectroscopic/photometric mini-survey of the sky over a few square degrees. Thanks to its large field of view, ANIS would be complementary to NGST. Its goal would be to probe the Universe in the 0 < z < 5 range and we can consider ANIS as a scientific precursor for the NGST.