# The Chandra Deep Field South as a test case for Global Multi Conjugate Adaptive Optics

## TL;DR

This paper demonstrates that Global Multi Conjugate Adaptive Optics (GMCAO) significantly improves the quality of deep-field extragalactic observations, enabling high completeness and accurate morphological measurements with a simulated 40-meter class telescope.

## Contribution

It introduces and tests GMCAO in a realistic simulation of the Chandra Deep Field South, showing its effectiveness for extragalactic surveys with future large telescopes.

## Key findings

- 94.5% source detection completeness with SEXTRACTOR
- High agreement between recovered and true galaxy parameters
- GMCAO provides reliable adaptive optics correction for ELT observations

## Abstract

The era of the next generation of giant telescopes requires not only the advent of new technologies but also the development of novel methods, in order to exploit fully the extraordinary potential they are built for. Global Multi Conjugate Adaptive Optics (GMCAO) pursues this approach, with the goal of achieving good performance over a field of view of a few arcmin and an increase in sky coverage. In this article, we show the gain offered by this technique to an astrophysical application, such as the photometric survey strategy applied to the Chandra Deep Field South as a case study. We simulated a close-to-real observation of a 500 x 500 arcsec^2 extragalactic deep field with a 40-m class telescope that implements GMCAO. We analysed mock K-band images of 6000 high-redshift (up to z = 2.75) galaxies therein as if they were real to recover the initial input parameters. We attained 94.5 per cent completeness for source detection with SEXTRACTOR. We also measured the morphological parameters of all the sources with the two-dimensional fitting tools GALFIT. The agreement we found between recovered and intrinsic parameters demonstrates GMCAO as a reliable approach to assist extremely large telescope (ELT) observations of extragalactic interest.