Bibcode
López-Sanjuan, C.; Balcells, M.; Pérez-González, Pablo G.; Barro, Guillermo; García-Dabó, C. E.; Gallego, Jesús; Zamorano, Jaime
Bibliographical reference
The Astrophysical Journal, Volume 710, Issue 2, pp. 1170-1178 (2010).
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2
2010
Journal
Citations
39
Refereed citations
36
Description
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 sun, 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 sun 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 sun 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 sun) galaxies since z ~ 1.
Related projects
Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
Ignacio
Martín Navarro