arXiv subjects

Claude Collin

Publications and source records attributed to Claude Collin.

5 recordsLinked to original sources

arXiv2026

The MICADO first-light imager for the ELT: first steps of the SCAO system MAIT

MICADO is the ELT first light instrument, an imager working at the diffraction limit of the telescope thanks to two adaptive optics (AO) modes: a single conjugate one (SCAO), available at the instrument first light and developed by the MICADO consortium, and a multi conjugate one (MCAO), developed by the MORFEO consortium. Although the project final design review process is about to be completed, the review board and ESO acknowledged that "the review of the final design can be considered complete for the majority of the MICADO sub-systems" and agreed that MICADO can start manufacturing. For the MICADO SCAO module, we have started the manufacturing of several parts: the majority of the SCAO optics and of the SCAO mechanics, the real-time computer software and the instrument control software. This manufacturing is ordered in several steps to allow the progressive integration of a first full AO close loop with the final SCAO parts. In this contribution, we will focus on the first two steps: on our AO S\'esame bench and the so-called "beta flat configuration". We will present the status of this manufacturing and the first results obtained.

astro-ph.IM↗

arXiv2026

The MICADO first light imager for the ELT: the SCAO module AIT in France, from the beta flat configuration towards the flat and final configurations

MICADO is the designated ELT first light instrument, a near-infrared imager working at the diffraction limit of the telescope thanks to a SCAO and an MCAO mode. Since summer 2024, MICADO is in its AIT phase and all MICADO partners are currently integrating their subsystems. The MICADO SCAO module will follow three successive AIT phases in France: the beta flat configuration, the flat configuration and the final configuration. In this contribution I will first present the progress made in the AIT of the beta flat configuration and its closed loop results. I will then present the performed and on-going tasks for the flat and final configurations (manufacturing, delivery and integration of several SCAO subsystems and pieces of software) and the results obtained so far in the flat configuration. I will then conclude with the expected following steps of the SCAO module AIT in Garching.

astro-ph.IM↗

arXiv2023

Monitoring fast solar chromospheric activity: the MeteoSpace project

We present in this reference paper an instrumental project dedicated to the monitoring of solar activity during solar cycle 25. It concerns the survey of fast evolving chromospheric events implied in Space Weather, such as flares, coronal mass ejections, filament instabilities and Moreton waves. Coronal waves are produced by large flares around the solar maximum and propagate with chromospheric counterparts; they are rare, faint, difficult to observe, and for that reason, challenging. They require systematic observations with automatic, fast and multi-channel optical instruments. MeteoSpace is a high cadence telescope assembly specially designed for that purpose. The large amount of data will be freely available to the solar community. We describe in details the optical design, the qualification tests and capabilities of the telescopes, and show how waves can be detected. MeteoSpace will be installed at Calern observatory (C{\^o}te d'Azur, 1270 m) and will be in full operation in 2023.

astro-ph.IM↗

arXiv2021

The SuperCam Infrared Spectrometer for the Perseverance Rover of the Mars2020 mission

We present the Infrared spectrometer of SuperCam Instrument Suite that enables the Mars 2020 Perseverance Rover to study remotely the Martian mineralogy within the Jezero crater. The SuperCam IR spectrometer is designed to acquire spectra in the 1.3-2.6 $\mu$m domain at a spectral resolution ranging from 5 to 20~nm. The field-of-view of 1.15 mrad, is coaligned with the boresights of the other remote-sensing techniques provided by SuperCam: laser-induced breakdown spectroscopy, remote time-resolved Raman and luminescence spectroscopies, and visible reflectance spectroscopy, and micro-imaging. The IR spectra can be acquired from the robotic-arm workspace to long-distances, in order to explore the mineralogical diversity of the Jezero crater, guide the Perseverance Rover in its sampling task, and to document the samples' environment. We present the design, the performance, the radiometric calibration, and the anticipated operations at the surface of Mars.

astro-ph.EP↗

arXiv2018

Multiple Star Systems in the Orion Nebula

This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium Cluster with the recently comissioned GRAVITY instrument. We observe a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for $\theta ^1$ Ori B, $\theta ^2$ Ori B, and $\theta ^2$ Ori C. We determine a separation for the previously suspected companion of NU Ori. We confirm four companions for $\theta ^1$ Ori A, $\theta ^1$ Ori C, $\theta ^1$ Ori D, and $\theta ^2$ Ori A, all with substantially improved astrometry and photometric mass estimates. We refine the orbit of the eccentric high-mass binary $\theta ^1$ Ori C and we are able to derive a new orbit for $\theta ^1$ Ori D. We find a system mass of 21.7 $M_{\odot}$ and a period of $53$ days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about 2, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints towards a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We exclude collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion.

astro-ph.SR↗