Physical conditions of the gas in an ALMA C II -identified submillimetre galaxy at z=4.44
Journal article, 2013

We present (CO)-C-12(2-1) observations of the submillimetre galaxy ALESS65.1 performed with the Australia Telescope Compact Array (ATCA) at 42.3 GHz. A previous Atacama Large Millimeter Array study of submillimetre galaxies (SMGs) in the Extended Chandra Deep Field South detected [C II] 157.74 mu m emission from this galaxy at a redshift of z= 4.44. No (CO)-C-12(21) emission was detected but we derive a firm upper limit to the cold gas mass in ALESS65.1 of M-gas < 1.7 x 10(10)M(circle dot). The estimated gas depletion time-scale is < 50 Myr, which is similar to other high-redshift SMGs, and consistent with z > 4 SMGs being the likely progenitors of massive red-and-dead galaxies at z > 2. The ratio of the [CII], (CO)-C-12 and far-infrared luminosities implies a strong far-ultraviolet field of G(0) greater than or similar to 103, as seen in Galactic star-forming regions or local ultraluminous infrared galaxies (ULIRGs). The observed L-[C II]/L-FIR = 2.3 x 10(-3) is high compared to local ULIRGs and, combined withLL([CII])/L-CO greater than or similar to 2700, it is consistent with ALESS65.1 either having an extended (several kpc) [C II] emitting region or lower than solar metallicity.

galaxy evolution

galaxy formation



M. T. Huynh

R. P. Norris

K. E. K. Coppin

B. Emonts

R. J. Ivison

N. Seymour

I. Smail

V. Smolcic

A. M. Swinbank

W. N. Brandt

S. C. Chapman

H. Dannerbauer

C. De Breuck

T. R. Greve

J. A. Hodge

A. Karim

Kirsten Kraiberg Knudsen

Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics

K. M. Menten

P.P. van der Werf

F. Walter

A. Weiss

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 431 1 L88-L92

Subject Categories

Astronomy, Astrophysics and Cosmology


Basic sciences



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