Establishing the Roman Population II Distance Ladder
| Program ID | 19018 |
|---|---|
| Science Category | Stellar Populations |
| Program Type | Analysis |
| Category | Medium |
| Principal Investigator | Meredith Durbin |
| PI Institution | University of California, Berkeley |
| Co-Investigators |
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| Abstract | We propose to establish the first absolute calibration of the Population II cosmic distance ladder in the Roman photometric system. The medium tier of the High Latitude Wide Area Survey and the astrometric touchstone field in the Large Magellanic Cloud will provide an unparalleled dataset of wide area, high resolution, and exquisitely calibrated imaging of a diverse sample of nearby galaxies. With these data we will be able to self-consistently calibrate and cross-validate three crucial distance indicators: RR Lyrae variable stars (RRL), the tip of the red giant branch (TRGB), and surface brightness fluctuations (SBF). Together, these distance indicators will enable a wide range of science in several of Roman's Core Community Surveys and throughout the lifetime of the Roman mission, including 3D studies of the inner Milky Way, mapping of large-scale structure and galaxy flows, and measurements of the Hubble constant. |