Molecular Gas in the z = 1.2 Ultraluminous Merger GOODS J123634.53+621241.3
Abstract
We report the detection of CO(2→1) emission from the z = 1.2 ultraluminous infrared galaxy (ULIRG) GOODS J123634.53+621241.3 (also known as the submillimeter galaxy GN 26). These observations represent the first discovery of high-redshift CO emission using the new Combined Array for Research in Millimeter-Wave Astronomy (CARMA). Of all high-redshift (z > 1) galaxies within the GOODS-North field, this source has the largest far-infrared (FIR) flux observed in the Spitzer 70 and 160 μm bands. The CO redshift confirms the optical identification of the source, and the bright CO(2→1) line suggests the presence of a large molecular gas reservoir of about 7 × 1010 M⊙. The infrared-to-CO luminosity ratio of L(IR)/L'(CO) = 80 +/- 30 L⊙ (K km s-1 pc2)-1 is slightly smaller than the average ratio found in local ULIRGs and high-redshift submillimeter galaxies. The short star formation timescale of about 70 Myr is consistent with a starburst associated with the merger event and is much shorter than the timescales for spiral galaxies and estimates made for high-redshift galaxies selected on the basis of their B - z and z - K colors.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2008
- DOI:
- 10.1086/589830
- arXiv:
- arXiv:0805.0321
- Bibcode:
- 2008ApJ...680L..21F
- Keywords:
-
- galaxies: evolution;
- galaxies: formation;
- galaxies: individual: GOODS J123634.53+621241.3;
- galaxies: starburst;
- Astrophysics
- E-Print:
- Accepted for publication in ApJ Letters