STAR FORMATION AND DUST OBSCURATION AT z ≈ 2: GALAXIES AT THE DAWN OF DOWNSIZING

被引：305

作者：

Pannella, M. ^{[1
]}

Carilli, C. L. ^{[1
]}

Daddi, E. ^{[2
]}

McCracken, H. J. ^{[3
]}

Owen, F. N. ^{[1
]}

Renzini, A. ^{[4
]}

Strazzullo, V. ^{[1
]}

Civano, F. ^{[5
]}

Koekemoer, A. M. ^{[6
]}

Schinnerer, E. ^{[7
]}

Scoville, N. ^{[8
]}

Smolcic, V. ^{[8
]}

Taniguchi, Y. ^{[9
]}

Aussel, H. ^{[2
]}

Kneib, J. P. ^{[10
]}

Ilbert, O. ^{[11
,12
]}

Mellier, Y. ^{[3
]}

Salvato, M. ^{[8
]}

Thompson, D. ^{[13
]}

Willott, C. J. ^{[14
]}

机构：

[1] Natl Radio Astron Observ, Socorro, NM 87801 USA

[2] Univ Paris Diderot, CNRS, CEA, Lab AIM,Irfu SAp, F-91191 Gif Sur Yvette, France

[3] Inst Astrophys, F-75014 Paris, France

[4] Osserv Astron Padova, INAF, I-35122 Padua, Italy

[5] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA

[6] Space Telescope Sci Inst, Baltimore, MD 21218 USA

[7] Max Planck Inst Astron, D-69117 Heidelberg, Germany

[8] CALTECH, Pasadena, CA 91125 USA

[9] Ehime Univ, Grad Sch Sci & Engn, Bunkyo, Matsuyama 7908577, Japan

[10] Lab Astrophys Marseille, F-13388 Marseille 13, France

[11] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA

[12] Lab Astrophys Marseille, F-13376 Marseille 12, France

[13] Univ Arizona, Large Binocular Telescope Observ, Tucson, AZ USA

[14] Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada

来源：

ASTROPHYSICAL JOURNAL LETTERS | 2009年 / 698卷 / 02期

关键词：

galaxies: evolution; galaxies: fundamental parameters; galaxies: ISM; galaxies: luminosity function; mass function; galaxies: statistics; surveys; VLA-COSMOS SURVEY; ACTIVE GALACTIC NUCLEI; FORS-DEEP-FIELD; GOODS-S-FIELD; MASSIVE GALAXIES; STELLAR MASS; SUBMILLIMETER GALAXIES; FORMATION HISTORY; FORMING GALAXIES; FORMATION RATES;

D O I：

10.1088/0004-637X/698/2/L116

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present first results of a study aimed to constrain the star formation rate (SFR) and dust content of galaxies at z approximate to 2. We use a sample of BzK-selected star-forming galaxies, drawn from the Cosmic Evolution Survey, to perform a stacking analysis of their 1.4 GHz radio continuum as a function of different stellar population properties, after cleaning the sample from contamination by active galactic nuclei. Dust unbiased SFRs are derived from radio fluxes assuming the local radio-IR correlation. The main results of this work are: (1) specific star formation rate (SSFR) s are constant over about 1 dex in stellar mass and up to the highest stellar mass probed, (2) the dust attenuation is a strong function of galaxy stellar mass with more massive galaxies being more obscured than lower mass objects, (3) a single value of the UV extinction applied to all galaxies would lead to a gross underestimate of the SFR in massive galaxies, (4) correcting the observed UV luminosities for dust attenuation based on the Calzetti recipe provides results in very good agreement with the radio derived ones, (5) the mean SSFR of our sample steadily decreases by a factor of similar to 4 with decreasing redshift from z = 2.3 to 1.4 and a factor of similar to 40 down the local universe. These empirical SFRs would cause galaxies to dramatically overgrow in mass if maintained all the way to low redshifts; we suggest that this does not happen because star formation is progressively quenched, likely starting from the most massive galaxies.

引用

页码：L116 / L120

页数：5

共 53 条

[21] Cold streams in early massive hot haloes as the main mode of galaxy formation [J].