Flexible Stellar Density Profiles of Dwarf Spheroidal Galaxies
Abstract
The Milky Way's satellite dwarf spheroidal galaxies (dSphs) are excellent laboratories to study galaxy formation, dark matter, and cosmology. While significant time has been invested in measuring their mass profiles, relatively little attention has been paid to their stellar density profiles, even though the stellar distribution provides half of the phase space information used to determine the mass profile. In particular, most stellar profiles are fit by models with only one or two shape parameters, which a priori fix the central and outer logarithmic slopes. We present a more flexible stellar profile for dSphs as a sum of generalized Plummer profiles. We use mock data to demonstrate that our model has sufficient freedom to distinguish steep central profiles ('cusped') from flattened ('cored') profiles. We apply our model to 37 real dSphs using large-scale survey data and find several dSphs that show evidence for outer slopes steeper than Plummer profiles: Draco, Leo I, Leo II, Reticulum II, and Fornax.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23516804M