Connecting Morphological Transformation to Rapid Quenching: Resolving the Structure of z~1 Post-Starburst Galaxies with Roman
| Program ID | 19068 |
|---|---|
| Science Category | Galaxies |
| Program Type | Analysis |
| Category | Small |
| Principal Investigator | Justin Spilker |
| PI Institution | Texas A & M University |
| Co-Investigators |
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| Abstract | Massive quiescent galaxies at high redshift provide a crucial window into the interplay between gas fueling, star formation, and galaxy morphology/kinematics. The growth of the red sequence at early times is dominated by galaxies that formed most of their mass in a single burst before rapidly quenching star formation, and JWST has now identified a few of these quenched 'post-starburst' galaxies as early as z > 3. While local post-starbursts are almost all major merger systems, virtually none at z > 3 show merger signatures, implying a strong change in this population over cosmic time. We propose a uniform and comprehensive morphological study of post-starbursts at redshifts spanning 6Gyr of evolution around cosmic noon. Thousands of massive post-starbursts have been found, and their formation histories measured, from large ground-based spectroscopic surveys like SDSS and DESI, but ground-based imaging cannot measure the structure of these compact systems. With a flexible analysis plan centered on the Roman HLWAS Medium-tier imaging, we will systematically measure the morphology and merger fraction in a sample of spectroscopically-selected post-starbursts that will grow to >10x larger than existing studies over the course of the HLWAS survey. The addition of space-based imaging to the large investments made by ground-based spectral surveys will offer qualitatively new constraints on the origin and evolution of post-starbursts at an epoch that fills the gap between local-universe studies and the small-sample surveys being done with JWST at earlier times. |