Mapping Circumgalactic Dust
| Program ID | 19001 |
|---|---|
| Science Category | Galaxies |
| Program Type | Analysis |
| Category | Small |
| Principal Investigator | Dennis Zaritsky |
| PI Institution | University of Arizona, Steward Observatory |
| Co-Investigators |
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| Abstract | Roman images will enable us to map dust within individual galactic halos (circumgalactic dust or CGD) and, by doing so, advance our understanding of galactic feedback, the nature of dark matter, and mitigate a remaining systematic unknown in cosmological surveys. We introduce the existing evidence for CGD and our limited knowledge of its properties. We argue 1) that this dust provides an opportunity to study the poorly understood circumgalactic medium (CGM), with the goal of developing a better understanding of the baryon cycle of galaxies, 2) that we can use the CGD to constrain dark matter halo profiles and thereby the nature of dark matter, and 3) that we must understand the CGD to realize the promised higher precision cosmological measurements from current and future surveys. We describe our methodology, including preliminary ground-based results that prove feasibility, and why archival Roman images present a unique opportunity to firmly establish the field of CGD mapping. |