1209.4086 (Mercedes Prieto et al.)

Evolutionary paths among different red galaxy types at 0.3 < z < 1.5 and the late buildup of massive E-S0's through major mergers    [PDF]

Mercedes Prieto, M. Carmen Eliche-Moral, Marc Balcells, David Cristobal-Hornillos, Peter Erwin, David Abreu, Lilian Dominguez-Palmero, Angela Hempel, Carlos Lopez-Sanjuan, Rafael Guzman, Pablo G. Perez-Gonzalez, Guillermo Barro, Jesus Gallego, Jaime Zamorano

Some recent observations seem to disagree with hierarchical theories of galaxy formation about the role played by major mergers in the late buildup of massive E-S0's. We re-address this question by analysing the morphology, structural distortion level, and star formation enhancement of a sample of massive galaxies (M_* > 5 * 10^10 Msun) lying on the Red Sequence and its surroundings at 0.3 < z < 1.5. We have used an initial sample of ~1800 sources with K_s < 20.5 mag over an area ~155 arcmin^2 on the Groth Strip, combining data from the Rainbow Extragalactic Database and the GOYA Survey. Red galaxy classes that can be directly associated to intermediate stages of major mergers and to their final products have been defined. We report observational evidence of the existence of a dominant evolutionary path among massive red galaxies at 0.6 10^11 Msun at z=0 through gas-rich major mergers has frozen since z~0.6. All these facts support that major mergers have played the dominant role in the definitive buildup of present-day E-S0's with M_*> 10^11 Msun at 0.6View original: http://arxiv.org/abs/1209.4086