Constructing the Largest Galaxy Sample at z>10 with Roman
| Program ID | 19006 |
|---|---|
| Science Category | Galaxies |
| Program Type | Analysis |
| Category | Small |
| Principal Investigator | Yuichi Harikane |
| PI Institution | University of Tokyo |
| Co-Investigators |
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| Abstract | Understanding when and how the first galaxies formed is one of the most fundamental questions in modern astronomy. One of the most striking discoveries from the first three years of observations with the James Webb Space Telescope (JWST) is the unexpectedly large number of bright galaxies at redshifts z>10. Their observed number density is significantly higher than theoretical predictions made prior to JWST's launch, suggesting that the physics governing early galaxy and star formation may differ substantially from that in the later universe. Despite intensive theoretical and observational efforts, the physical origin of this discrepancy remains unclear. A key limitation is that the current samples of bright z>10 galaxies are still small because existing surveys with JWST cover relatively limited areas, preventing robust statistical studies. In this proposal, we will construct the largest sample of bright galaxies at z>10 using imaging data from the multiple Roman Core Community Surveys (CCS). With a field of view orders of magnitude larger than JWST surveys, the Roman datasets will enable the identification of N>20,000 bright galaxies at z>10 over unprecedented survey volumes. This large sample, ~100 times larger than those currently available from JWST, will allow us to accurately measure the bright end of the galaxy luminosity function and angular correlation functions at these redshifts to investigate the physical origin of the overabundance of the bright galaxies seen by JWST. Furthermore, the exceptional brightness of these galaxies will make them ideal targets for detailed spectroscopic follow-up with JWST and ALMA. These observations will allow us to investigate their chemical enrichment, kinematics, and stellar populations, providing unique insight into the formation of the first galaxies, the emergence of the first supermassive black holes, and possible signatures of Population III stars. |