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Inferring the star formation histories of the most massive and passive early-type galaxies at z<0.3
- Publication Year :
- 2016
-
Abstract
- Massive galaxies are key probes to understand how the baryonic matter evolves within the dark matter halos. We use the "archaeological" approach to infer the stellar population properties and star formation histories of the most massive (M > 10^10.75 Msun) and passive early-type galaxies (ETGs) at 0 < z < 0.3, based on stacked, high signal to noise ratio (SNR), Sloan Digital Sky Survey spectra. We exploit the information present in the full-spectrum by means of the STARLIGHT public code to retrieve the ETGs evolutionary properties, such as age, metallicity and star formation history. We find that the stellar metallicities are slightly supersolar (Z ~ 0.027 +/- 0.002) and do not depend on redshift. Dust extinction is very low, with a mean of Av ~ 0.08 +/- 0.03 mag. The ETGs show an anti-hierarchical evolution (downsizing) where more massive galaxies are older. The SFHs can be approximated by a parametric function of the form SFR(t) \propto \tau^-(c+1) t^(c) exp(-t/\tau), with typical short e-folding times of \tau ~ 0.6 - 0.8 Gyr (and a dispersion of +/- 0.1 Gyr) and c ~ 0.1 (and a dispersion of +/- 0.05). The inferred SFHs are also used to place constraints on the properties and evolution of the ETG progenitors. In particular, the ETGs of our samples should have formed most stars through a phase of vigorous star formation (SFRs > 350-400 Msun yr^-1) at z ~ 4 - 5, and are quiescent by z ~ 1.5 -2. Our results represent an attempt to demonstrate quantitatively the evolutionary link between the most massive ETGs at z < 0.3 and the properties of suitable progenitors at high redshifts, also showing that the full-spectrum fitting is a powerful approach to reconstruct the star formation histories of massive quiescent galaxies.<br />Comment: 25 pages, 25 figures, 4 tables. Accepted for publication in Astronomy & Astrophysics
- Subjects :
- Physics
Cold dark matter
Stellar population
Stellar mass
010308 nuclear & particles physics
Star formation
Metallicity
Dark matter
Galaxies: evolution
Astronomy and Astrophysics
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astronomy and Astrophysic
01 natural sciences
Astrophysics - Astrophysics of Galaxies
Galaxy
Stars
Space and Planetary Science
0103 physical sciences
galaxies: stellar content
galaxies: formation
Astrophysics::Solar and Stellar Astrophysics
Astrophysics::Earth and Planetary Astrophysics
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....8d612f7a096601d2c2b0f7cfb3d845de