RT Journal Article
T1 The minor role of gas-rich major mergers in the rise of intermediate-mass early types at z ≤ 1
A1 López Sanjuan, Carlos
A1 Balcells, Marc
A1 Pérez González, Pablo Guillermo
A1 Barro, Guillermo
A1 García Dabó, César Enrique
A1 Gallego Maestro, Jesús
A1 Zamorano Calvo, Jaime
AB We study the evolution of galaxy structure since z ~ 1 to the present. From a Great Observatories Origins Deep Survey South (GOODS-S) multi-band catalog, we define (blue) luminosity- and mass-weighted samples, limited by MB ≤ –20 and M  sstarf ≥ 1010 M ☉, comprising 1122 and 987 galaxies, respectively. We extract early-type (ET; E/S0/Sa) and late-type (LT; Sb-Irr) subsamples by their position in the concentration-asymmetry plane, in which galaxies exhibit a clear bimodality. We find that the ET fraction, f ET, rises with cosmic time, with a corresponding decrease in the LT fraction, f LT, in both luminosity- and mass-selected samples. However, the evolution of the comoving number density is very different: the decrease in the total number density of MB ≤ –20 galaxies since z = 1 is due to the decrease in the LT population, which accounts for ~75% of the total star formation rate in the range under study, while the increase in the total number density of M  sstarf ≥ 1010 M ☉ galaxies in the same redshift range is due to the evolution of ETs. This suggests that we need a structural transformation between LT galaxies that form stars actively and ET galaxies in which the stellar mass is located. Comparing the observed evolution with the gas-rich major merger rate in GOODS-S, we infer that only ~20% of the new ET galaxies with M  sstarf ≥ 1010 M ☉ appeared since z ~ 1 can be explained by this kind of mergers, suggesting that minor mergers and secular processes may be the driving mechanisms of the structural evolution of intermediate-mass (M  sstarf ~ 4 × 1010 M ☉) galaxies since z ~ 1.
PB American Astronomical Society
SN 0004-637X
YR 2010
FD 2010-02-20
LK https://hdl.handle.net/20.500.14352/44784
UL https://hdl.handle.net/20.500.14352/44784
LA eng
NO © 2010. The American Astronomical Society. This work was supported by the Spanish Programa Nacional de Astronomía y Astrofísica through the project numbers AYA2006-12955, AYA2006-02358, and AYA 2006-15698-C02-02. This work was partially funded by the Spanish MEC under the Consolider-Ingenio 2010 Program grant CSD2006-00070: First Science with the GTC (http://www.iac.es/consolider-ingenio-gtc/).This work is based on HST/ACS images from GOODS HST Treasury Program, which is supported by NASA through grants HST-GO-09425.01-A and HST-GO-09583.01, and in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, Caltech under NASA contract 1407.P. G. P. G. acknowledges support from the Ramón y Cajal Program financed by the Spanish Government and the European Union.
NO Programa Nacional de Astronomía y Astrofísica (MICINN), España
NO Ministerio de Educación y Ciencia (MEC), España
NO National Aeronautics and Space Administration (NASA)
NO Gobierno de España
NO Unión Europea (UE)
NO Programa Consolider-Ingenio (MINECO), España
NO Ministerio de Economía y Competitividad (MINECO), España
NO GOODS HST Treasury Program (NASA)
NO Jet Propulsion Laboratory, Caltech
NO Programa Ramón y Cajal
DS Docta Complutense
RD 18 dic 2025