Astro2020: Empirically Constraining Galaxy Evolution
  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.
