Kathryn Johnston

Methods - Sanity Checks
- 11 satellites of Milky Way (similar number for M31)
=> how many baryons to assign to each dark satellite (via
“squelching” of low end of luminosity function due to re-ionization -
see Bullock, Kravtsov & Weinberg, 2000)
- field dwarfs have significant gas content (e.g. Grebel et al , 2003)
=> how fast to turn baryons into stars (i.e. long timescale for star
formation, consistent with earlier talks...)
- field dwarfs follow well defined correlations in luminosity and core
radius (e.g. Mateo, 1998)
=> how to embed stars within halos
In addition, the model fits:
(i) stellar halo luminosity;
(ii) Hernquist profile;
(iii) distribution of satellite structural properties.