Feedback and the formation of dwarf galaxy stellar haloes

Abstract

Stellar population studies show that low-mass galaxies in all environments exhibit stellar haloes that are older and more spherically distributed than the main body of the galaxy. In some cases, there is a significant intermediate age component that extends beyond the young disc. We examine a suite of Smoothed Particle Hydrodynamic simulations and find that elevated early star formation activity combined with supernova feedback can produce an extended stellar distribution that resembles these haloes for model galaxies ranging from v 200 = 15 to 35 km s-1, without the need for accretion of subhaloes. © 2009 RAS.