Beyond the UVLF: High-redshift galaxy clustering with Roman
| Program ID | 19031 |
|---|---|
| Science Category | Galaxies |
| Program Type | Analysis |
| Category | Medium |
| Principal Investigator | Julian Munoz |
| PI Institution | University of Texas, Austin |
| Co-Investigators |
|
| Abstract | The formation of the first galaxies is one of the major open questions in astrophysics. Current observations of UV luminosity functions suffer from intrinsic degeneracies, as very different galaxy-formation models can produce identical number counts. Galaxy clustering can break them by linking observed galaxies to their dark-matter host halos, and Roman uniquely combines the depth, area, and filter coverage to precisely measure clustering at z > 6, beyond the reach of current facilities. While Roman will revolutionize high-z clustering measurements, careful modeling will be required to understand them. We propose a theory program to interpret Roman’s measurements of galaxy clustering at high redshifts with three goals: (i) model galaxy bias at z > 9 to determine whether the JWST excess of UV-bright galaxies is due to enhanced star-formation efficiency or enhanced burstiness; (ii) map how the UV stochasticity depends on both halo mass and redshift across z = 6−11, distinguishing between competing feedback models; (iii) model the full two-point correlation function beyond the bias, constraining satellite fractions and the halo occupation distribution at high z for the first time. We will deliver a fully public pipeline to predict UVLFs and clustering jointly, validated against state-of-the-art simulations and applied to Roman HLWAS-Deep and Medium data. This program will maximize Roman’s returns by providing a publicly available theoretical pipeline needed to understand its clustering measurements. New data requires new tools, which this proposal will provide. |