Physical conditions of the gas in an ALMA [ C II ] - identified submillimetre
نویسندگان
چکیده
We present 12CO(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 μm emission from this galaxy at a redshift of z= 4.44. No 12CO(2– 1) emission was detected but we derive a firm upper limit to the cold gas mass in ALESS65.1 of Mgas < 1.7 × 1010 M . 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 [C II], 12CO and far-infrared luminosities implies a strong far-ultraviolet field of G0 103, as seen in Galactic star-forming regions or local ultraluminous infrared galaxies (ULIRGs). The observed L[C II]/LFIR = 2.3 × 10−3 is high compared to local ULIRGs and, combined withL[C II]/LCO 2700, it is consistent with ALESS65.1 either having an extended (several kpc) [C II] emitting region or lower than solar metallicity.
منابع مشابه
Physical Conditions of the Gas in an ALMA [ CII ] - identified Submillimetre Galaxy at z = 4 . 44
We present CO(2–1) observations of the submillimetre galaxy ALESS65.1 performed with the Australia Telescope Compact Array at 42.3 GHz. A previous ALMA study of submillimetre galaxies in the Extended Chandra Deep Field South detected [CII] 157.74 μm emission from this galaxy at a redshift of z = 4.44. No CO(2–1) emission was detected but we derive a firm upper limit to the cold gas mass in ALES...
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