1202.5403 (A. Cimatti et al.)

Fast evolving size of early-type galaxies at z>2 and the role of dissipationless (dry) merging    [PDF]

A. Cimatti, C. Nipoti, P. Cassata

We present the analysis of a large sample of early-type galaxies (ETGs) at 02 are removed from the sample, suggesting an accelerated increase of the typical sizes at z>2, especially for the ETGs with the largest masses. A pure dry merging LambdaCDM model is marginally consistent with the average size evolution at 02 progenitor ETGs. This opens the crucial question on what physical mechanism can explain the accelerated evolution at z>2, or whether an unclear observational bias is partly responsible for that.

View original: http://arxiv.org/abs/1202.5403