A Rapid Path to High-Impact Early Science: Roman Characterization of Faint Local Volume Dwarf Candidates
| Program ID | 19014 |
|---|---|
| Science Category | Stellar Populations |
| Program Type | Analysis |
| Category | Small |
| Principal Investigator | Burcin Mutlu-Pakdil |
| PI Institution | Dartmouth College |
| Co-Investigators |
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| Abstract | Dwarf galaxies provide some of the most sensitive tests of dark matter and galaxy formation on the smallest scales. However, the current sample of the faintest galaxies beyond the Local Group remains extremely limited and is largely centered on satellite populations, risking models being over-tailored to a specific environment. A robust test of these models requires extending the dwarf galaxy census to both new environments and fainter systems. We propose to use archival imaging from the first two years of the High Latitude Wide Area Medium-tier surveys to characterize newly identified faint dwarf galaxy candidates in the Local Volume (within 5 Mpc). These systems were uncovered in wide-area ground-based imaging using machine-learning techniques optimized for the semi-resolved regime, where extremely faint galaxies appear partially resolved and evade traditional discovery methods. This sample represents the first untargeted sample of faint dwarfs not restricted to satellite systems. Roman's multi-filter imaging will resolve these systems into individual stars several magnitudes below the tip of the red giant branch, enabling robust distance measurements and detailed characterization of their stellar populations and structural properties. Starting from a pre-identified candidate sample provides a rapid, low-risk path to early science, enabling efficient characterization of hundreds of faint dwarf candidates in the Local Volume. This program will transform the current small and heterogeneous set of known faint Local Volume dwarfs into the first statistically meaningful sample of the faintest dwarf galaxies spanning diverse environments, from satellites of nearby hosts to truly isolated systems. The resulting dataset will enable a direct assessment of environmental effects and reionization at the lowest mass scales. As a uniformly characterized and environmentally diverse sample, it will establish a new benchmark for studies of the faint frontier of galaxy formation. |