Sweating the small stuff: simulating dwarf galaxies, ultra-faint dwarf galaxies, and their own tiny satellites

• DOI: 10.1093/mnras/stv1691
• Publication Date: 2015-08-24T20:34:56Z
• Authors: Coral Wheeler; Jose Oñorbe; James S. Bullock; Michael Boylan-Ko...; Oliver D. Elbert; Shea Garrison-Kimmel; Philip F. Hopkins; Dušan Kereš
• Keywords: Dwarf galaxy problem; Local Group

We present FIRE/Gizmo hydrodynamic zoom-in simulations of isolated dark matter halos, two each at the mass classical dwarf galaxies ($M_{\rm vir} \simeq 10^{10} M_{\odot}$) and ultra-faint 10^9 M_{\odot}$), with feedback implementations. The resultant central lie on an extrapolated abundance matching relation from $M_{\star} 10^6$ to $10^4 M_{\odot}$ without a break. Every host is filled subhalos, many which form stars. Our dwarfs 10^6 have 1-2 well-resolved satellites = 3-200 \times 10^3 M_{\odot}$. Even our star-forming subhalos. If this representative, throughout universe should commonly tiny satellite their own. combine results ELVIS show that targeting $\sim 50~ \rm kpc$ regions around nearby could increase chances discovering by 35\%$ compared random halo pointings, specifically identify region Phoenix galaxy as good potential target. in ($M_{\star} 3 - 30 within $M_{\rm peak} 0.5 halos. Each has uniformly ancient stellar population ($ > 10~ Gyr$) owing reionization-related quenching. More massive systems, contrast, all late-time star formation. suggest halo} 5 probable dividing line between halos hosting reionization "fossils" those can continue stars isolation after reionization.