Ultra-deep Imaging: Structure of Disks and Haloes

TL;DR

Ultra-deep imaging of galaxy disks and haloes, utilizing advanced observational techniques, reveals detailed structures like stellar streams and haloes, offering insights into galaxy formation and evolution.

Contribution

This paper reviews recent technical advances and observational results in ultra-deep galaxy imaging, highlighting challenges and future prospects in the field.

Findings

Detection of stellar haloes and tidal features

Characterization of disk truncations and thick disks

Identification of stellar streams and streams

Abstract

Deep imaging is a fundamental tool in the study of the outermost structures of galaxies. We review recent developments in ultra-deep imaging of galaxy disks and haloes, highlighting the technical advances as well as the challenges, and summarizing observational results in the context of modern theory and simulations. The deepest modern galaxy imaging comes from three main sources: (1) surveys such as the Sloan Digital Sky Survey's Stripe 82 project, (2) very long exposures on small telescopes, including by amateurs, and (3) long exposures on the largest professional telescopes. The technical challenges faced are common in all these approaches, and include the treatment of light scattered by atmosphere and telescope/instrument, correct flat fielding, and the subtraction of non-galaxy light in the images. We review scientific results on galaxy disks and haloes obtained with deep imaging, including the detection and characterization of stellar haloes, tidal features and stellar streams, disk truncations, and thick disks. The area of ultra-deep imaging is still very much unexplored territory, and future work in this area promises significant advances in our understanding of galaxy formation and evolution.