THE REDSHIFT AND NATURE OF AzTEC/COSMOS 1: A STARBURST GALAXY AT z=4.6

Smolcic, V.; Capak, P.; Ilbert, O.; Blain, A. W.; Salvato, M.; Aretxaga, I.; Schinnerer, E.; Masters, D.; Moric, I.; Riechers, D. A.; Sheth, K.; Aravena, M.; Aussel, H.; Aguirre, J.; Berta, S.; et. al.

Abstract

Based on broadband/narrowband photometry and Keck DEIMO spectroscopy, we report a redshift of z = 4.64(-0.08)(+0.06) for AzTEC/COSMOS 1, the brightest submillimeter galaxy (SMG) in the AzTEC/COSMOS field. In addition to the COSMOS-survey X-ray to radio data, we report observations of the source with Herschel/PACS (100, 160 mu m), CSO/SHARC II (350 mu m), and CARMA and PdBI (3 mm). We do not detect CO(5 -> 4) line emission in the covered redshift ranges, 4.56-4.76 (PdBI/CARMA) and 4.94-5.02 (CARMA). If the line is within this bandwidth, this sets 3 sigma upper limits on the gas mass to less than or similar to 8 x 10(9) M-circle dot and less than or similar to 5 x 10(10) M-circle dot, respectively (assuming similar conditions as observed in z similar to 2 SMGs). This could be explained by a low CO-excitation in the source. Our analysis of the UV-IR spectral energy distribution of AzTEC 1 shows that it is an extremely young (less than or similar to 50 Myr), massive (M-* similar to 10(11) M-circle dot), but compact (less than or similar to 2 kpc) galaxy, forming stars at a rate of similar to 1300 M-circle dot yr(-1). Our results imply that AzTEC 1 is forming stars in a "gravitationally bound" regime in which gravity prohibits the formation of a superwind, leading to matter accumulation within the galaxy and further generations of star formation.

Más información

Título según WOS: ID WOS:000293128100006 Not found in local WOS DB
Título de la Revista: ASTROPHYSICAL JOURNAL LETTERS
Volumen: 731
Número: 2
Editorial: IOP PUBLISHING LTD
Fecha de publicación: 2011
DOI:

10.1088/2041-8205/731/2/L27

Notas: ISI