The star formation and extinction coevolution of UV-selected galaxies over 0.05 < z < 1.2



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Pérez González, Pablo Guillermo and otros, ... (2007) The star formation and extinction coevolution of UV-selected galaxies over 0.05 < z < 1.2. Astrophysical journal supplement series, 173 (2). pp. 415-431. ISSN 0067-0049

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We use a new stacking technique to obtain mean mid-IR and far-IR to far-UV flux ratios over the rest-frame near-UV, near-IR color-magnitude diagram. We employ COMBO-17 redshifts and COMBO-17 optical, GALEX far- and near-UV, and Spitzer IRAC and MIPS mid-IR photometry. This technique permits us to probe the infrared excess (IRX), the ratio of far-IR to far-UV luminosity, and the specific star formation rate (SSFR) and their coevolution over 2 orders of magnitude of stellar mass and over redshift 0.1 < z < 1.2. We find that the SSFR and the characteristic mass (Script M_0) above which the SSFR drops increase with redshift (downsizing). At any given epoch, the IRX is an increasing function of mass up to Script M_0. Above this mass the IRX falls, suggesting gas exhaustion. In a given mass bin below Script M_0, the IRX increases with time in a fashion consistent with enrichment. We interpret these trends using a simple model with a Schmidt-Kennicutt law and extinction that tracks gas density and enrichment. We find that the average IRX and SSFR follow a galaxy age parameter ξ, which is determined mainly by the galaxy mass and time since formation. We conclude that blue-sequence galaxies have properties which show simple, systematic trends with mass and time such as the steady buildup of heavy elements in the interstellar media of evolving galaxies and the exhaustion of gas in galaxies that are evolving off the blue sequence. The IRX represents a tool for selecting galaxies at various stages of evolution.

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© 2007 The American Astronomical Society. All rights reserved.
Artículo firmado por 25 autores.
GALEX (Galaxy Evolution Explorer) is a NASA Small Explorer, launched in 2003 April.We gratefully acknowledge NASA’s support for construction, operation, and science analysis for the GALEX mission, developed in cooperation with the Centre National d’Etudes Spatiales of France and the Korean Ministry of Science and Technology.

Uncontrolled Keywords:Ultraviolet luminosity density; Mass-metallicity relation; Forming galaxies; Stellar mass; Evolution-explorer; Combo-17 survey; Field galaxies; High-redshift; Deep fields; Spitzer
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
ID Code:38679
Deposited On:03 Aug 2016 13:47
Last Modified:10 Dec 2018 15:05

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