Dry mergers and the size evolution of early-type galaxies
arXiv:1109.1669
Abstract
Dry (i.e. dissipationless) merging has been proposed as the main driver of the observed size evolution of early-type galaxies (ETGs). The actual role of this mechanism is questioned by the tightness of the local stellar mass-size relation of ETGs. Combining this observed scaling law with simple merging models, which should bracket cosmologically motivated merging histories, we draw the following conclusions: 1) local massive ETGs can have assembled at most ~45% of their stellar mass via dry mergers; 2) extreme fine tuning is required for this to be the case.
arXiv comment4 pages, 1 figure, 1 table. To appear in "Advances in Computational Astrophysics: methods, tools and outcomes", ASP Conference Series, R. Capuzzo-Dolcetta, M. Limongi and A. Tornambè eds