Astro2020: Empirically Constraining Galaxy Evolution

TL;DR

This paper reviews recent progress and outlines future directions in empirically constraining the galaxy-dark matter halo connection to better understand galaxy evolution, emphasizing the need for broader spectroscopic data and improved survey practices.

Contribution

It highlights the importance of linking halo assembly histories with various galaxy properties and provides recommendations for future observational strategies.

Findings

Empirical constraints have advanced understanding of galaxy evolution.

Future techniques will connect halo histories with galaxy properties like morphology and metallicity.

Broader spectroscopic coverage and improved survey practices are essential for progress.

Abstract

Over the past decade, empirical constraints on the galaxy-dark matter halo connection have significantly advanced our understanding of galaxy evolution. Past techniques have focused on connections between halo properties and galaxy stellar mass and/or star formation rates. Empirical techniques in the next decade will link halo assembly histories with galaxies' circumgalactic media, supermassive black holes, morphologies, kinematics, sizes, colors, metallicities, and transient rates. Uncovering these links will resolve many critical uncertainties in galaxy formation and will enable much higher-fidelity mock catalogs essential for interpreting observations. Achieving these results will require broader and deeper spectroscopic coverage of galaxies and their circumgalactic media; survey teams will also need to meet several criteria (cross-comparisons, public access, and covariance matrices) to facilitate combining data across different surveys. Acting on these recommendations will continue enabling dramatic progress in both empirical modeling and galaxy evolution for the next decade.