Mapping the Dark Matter Halo Profiles of Spiral Galaxies with Weak Lensing
| Program ID | 19069 |
|---|---|
| Science Category | Galaxies |
| Program Type | Analysis |
| Category | Small |
| Principal Investigator | Yicheng Guo |
| PI Institution | University of Missouri |
| Co-Investigators |
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| Abstract | We propose a small Roman archival program to investigate the weak lensing effect around spiral galaxies at z ~ 0.75 by using the Deep tier of the High Latitude Wide Area Survey (HLWAS). We will run a deep learning algorithm to identify a large sample of face-on spiral galaxies, then perform a stacking analysis of their tangential shear profiles, reconstruct their dark matter halo mass profiles, and test if their halo profiles correlate with their internal properties. This study is uniquely enabled by Roman’s unprecedented combination of wide-field coverage, depth, and spatial resolution, which allows precise shape measurement of faint, high-redshift background galaxies necessary to map the halos. This program will provide stringent constraints on the halo-galaxy interaction in spiral galaxies 8 billion years ago and probe three fundamental relationships of galaxy assembly at z ~ 0.75: (1) galaxy--halo size relation, (2) halo concentration and central bulge formation, and (3) halo potential and dynamics of galaxies. By mapping these relationships across cosmic time, we will reveal whether dark matter halos remain the primary architect of spiral morphology or if the baryon cycles have decoupled galaxy structure from its dark matter halos at z ~ 0.75. |