期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 448, 期 4, 页码 3484-3513出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/stv105
关键词
galaxies: abundances; galaxies: elliptical and lenticular, cD; galaxies: evolution; galaxies: stellar content
资金
- Royal Society University Research Fellowship
- UK Research Councils [PP/E001114/1, ST/H002456/1, PPA/V/S/2002/00553, PP/E001564/1, ST/H504862/1]
- Christ Church, Oxford
- Royal Society [502011. K502/jd, JP0869822]
- DFG Cluster of Excellence Origin and Structure of the Universe
- STFC Advanced Fellowship [ST/F009186/1]
- ESO fellowship
- European Community [229517]
- ESO
- Australian Research Council [DP110103509]
- Alfred P. Sloan Foundation
- National Science Foundation
- US Department of Energy Office of Science
- University of Arizona
- Brazilian Participation Group
- Brookhaven National Laboratory
- Carnegie Mellon University
- University of Florida
- French Participation Group
- German Participation Group
- Harvard University
- Instituto de Astrofisica de Canarias
- Michigan State/Notre Dame/JINA Participation Group
- Johns Hopkins University
- Lawrence Berkeley National Laboratory
- Max Planck Institute for Astrophysics
- Max Planck Institute for Extraterrestrial Physics
- NewMexico State University
- New York University
- Ohio State University
- Pennsylvania State University
- University of Portsmouth
- Princeton University
- Spanish Participation Group
- University of Tokyo
- University of Utah
- Vanderbilt University
- University of Virginia
- University of Washington
- Yale University
- Direct For Mathematical & Physical Scien
- Division Of Astronomical Sciences [1109803] Funding Source: National Science Foundation
- Science and Technology Facilities Council [ST/L004496/2, ST/M001857/1, ST/F009186/1, PP/E001564/1, ST/K00106X/1, ST/H002456/1, ST/L004496/1, ST/H504862/1, PP/E001114/1] Funding Source: researchfish
- STFC [PP/E001564/1, ST/M001857/1, ST/H504862/1, ST/L004496/2, PP/E001114/1, ST/K00106X/1, ST/L004496/1, ST/H002456/1, ST/K005596/1, ST/F009186/1] Funding Source: UKRI
We present the stellar population content of early-type galaxies from the ATLAS(3D) survey. Using spectra integrated within apertures covering up to one effective radius, we apply two methods: one based on measuring line-strength indices and applying single stellar population (SSP) models to derive SSP-equivalent values of stellar age, metallicity, and alpha enhancement; and one based on spectral fitting to derive non-parametric star formation histories, mass-weighted average values of age, metallicity, and half-mass formation time-scales. Using homogeneously derived effective radii and dynamically determined galaxy masses, we present the distribution of stellar population parameters on the Mass Plane (M-JAM, sigma(e), R-e(maj)), showing that at fixed mass, compact early-type galaxies are on average older, more metal-rich, and more alpha-enhanced than their larger counterparts. From non-parametric star formation histories, we find that the duration of star formation is systematically more extended in lower mass objects. Assuming that our sample represents most of the stellar content of today's local Universe, approximately 50 per cent of all stars formed within the first 2 Gyr following the big bang. Most of these stars reside today in the most massive galaxies (>10(10.5) M-circle dot), which themselves formed 90 per cent of their stars by z similar to 2. The lower mass objects, in contrast, have formed barely half their stars in this time interval. Stellar population properties are independent of environment over two orders of magnitude in local density, varying only with galaxy mass. In the highest density regions of our volume (dominated by the Virgo cluster), galaxies are older, alpha-enhanced, and have shorter star formation histories with respect to lower density regions.
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