Building Roman’s Infant Galaxies with Hyper-refined Targeted FIRE Simulations
| Program ID | 19061 |
|---|---|
| Science Category | Galaxies |
| Program Type | Analysis |
| Category | Small |
| Principal Investigator | Guochao Sun |
| PI Institution | Northwestern University |
| Co-Investigators |
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| Abstract | Recent JWST observations have revealed an enigmatic population of UV-bright infant galaxies at $z\gtrsim10$, challenging standard models of early galaxy formation and motivating a new theoretical framework for the upcoming transformative Roman observations. Bright-FIRE will meet this need with a novel suite of cosmological MHD zoom-in simulations targeting the rare massive halos most relevant to Roman's discovery space, combining FIRE-3 physical models with the Lagrangian hyper-refinement technique to resolve the dense star-forming clouds, multiphase ISM, and stellar feedback processes that regulate early galaxy growth. Unlike large-box simulations that depend heavily on subgrid treatments, Bright-FIRE is uniquely positioned to resolve, from first principles, the star formation and feedback physics that set the star formation efficiency in Roman-relevant massive halos. The simulations will follow $\sim$20 massive halos to $z\sim9$, with a small subset further hyper-refined to test SFE convergence and probe possible IMF variations in intensely star-forming clouds at early times. They will also directly test whether the exceptional UV luminosities of Roman-selected galaxies are driven by genuinely enhanced SFEs or other mechanisms such as bursty star formation histories. By post-processing these simulations with radiative transfer and photoionization modeling to generate multi-wavelength synthetic observables for Roman and ancillary facilities, Bright-FIRE will deliver the theoretical foundation, physical interpretation, and mock data products urgently needed to fully exploit Roman's statistical census of bright infant galaxies at Cosmic Dawn. |