Dissecting Galaxies with Adaptive Optics

TL;DR

This paper discusses the use of adaptive optics in galaxy and black hole studies, emphasizing PSF modeling, resolution limits, and the importance of accurate kinematic measurements for high-resolution astrophysical observations.

Contribution

It introduces methods for PSF estimation and discusses the impact of signal-to-noise and resolution requirements in adaptive optics observations of galaxies.

Findings

PSF knowledge level affects model convolution accuracy

High signal-to-noise ratios improve resolution limits

Many science cases need high, but not diffraction-limited, resolution

Abstract

We describe several projects addressing the growth of galaxies and massive black holes, for which adaptive optics is mandatory to reach high spatial resolution but is also a challenge due to the lack of guide stars and long integrations. In each case kinematics of the stars and gas, derived from integral field spectroscopy, plays a key role. We explain why deconvolution is not an option, and that instead the PSF is used to convolve a physical model to the required resolution. We discuss the level of detail with which the PSF needs to be known, and the ways available to derive it. We explain how signal-to-noise can limit the resolution achievable and show there are many science cases that require high, but not necessarily diffraction limited, resolution. Finally, we consider what requirements astrometry and photometry place on adaptive optics performance and design.