English

GMagAO-X: A First Light Coronagraphic Adaptive Optics System for the GMT

Instrumentation and Methods for Astrophysics 2023-10-18 v1

Abstract

GMagAO-X is a visible to NIR extreme adaptive optics (ExAO) system that will be used at first light for the Giant Magellan Telescope (GMT). GMagAO-X is designed to deliver diffraction-limited performance at visible and NIR wavelengths (6 to 10 mas) and contrasts on the order of 10710^{-7}. The primary science case of GMagAO-X will be the characterization of mature, and potentially habitable, exoplanets in reflected light. GMagAO-X employs a woofer-tweeter system and includes segment phasing control. The tweeter is a 21,000 actuator segmented deformable mirror (DM), composed of seven individual 3,000 actuator DMs. This new ExAO framework of seven DMs working in parallel to produce a 21,000 actuator DM significantly surpasses any current or near future actuator count for a monolithic DM architecture. Bootstrapping, phasing, and high order sensing are enabled by a multi-stage wavefront sensing system. GMT's unprecedented 25.4 m aperture composed of seven segments brings a new challenge of co-phasing massive mirrors to 1/100th of a wavelength. The primary mirror segments of the GMT are separated by large >30 cm gaps so there will be fluctuations in optical path length (piston) across the pupil due to vibration of the segments, atmospheric conditions, etc. We have developed the High Contrast Adaptive-optics Testbed (HCAT) to test new wavefront sensing and control approaches for GMT and GMagAO-X, such as the holographic dispersed fringe sensor (HDFS), and the new ExAO parallel DM concept for correcting aberrations across a segmented pupil. The CoDR for GMagAO-X was held in September 2021 and a preliminary design review is planned for early 2024. In this paper we will discuss the science cases and requirements for the overall architecture of GMagAO-X, as well as the current efforts to prototype the novel hardware components and new wavefront sensing and control concepts for GMagAO-X on HCAT.

Cite

@article{arxiv.2310.10888,
  title  = {GMagAO-X: A First Light Coronagraphic Adaptive Optics System for the GMT},
  author = {Maggie Kautz and Jared R. Males and Laird M. Close and Sebastiaan Y. Haffert and Olivier Guyon and Alexander Hedglen and Victor Gasho and Olivier Durney and Jamison Noenickx and Adam Fletcher and Fernando Coronado and John Ford and Tom Connors and Mark Sullivan and Tommy Salanski and Doug Kelly and Richard Demers and Antonin Bouchez and Breann Sitarski and Patricio Schurter},
  journal= {arXiv preprint arXiv:2310.10888},
  year   = {2023}
}

Comments

16 pages, 22 figures, proceeding for AO4ELT7 (Avignon, France June 2023)