ISM Properties of a Massive Dusty Star-forming Galaxy Discovered at z ∼ 7
Menten, K. M.; Béthermin, M.; Murphy, E. J.; Weiss, A.; Greve, T. R.; Carlstrom, J. E.; Vieira, J. D.; Aravena, M.; Malkan, M.; Ashby, M. L. N.; Chen, Chian-Chou; Fassnacht, C. D.; Gonzalez, A. H.; Chapman, S. C.; Marrone, D. P.; De Breuck, C.; Bradford, C. M.; Gullberg, B.; Spilker, J. S.; Narayanan, D.; Hezaveh, Y.; Hayward, C. C.; Litke, K.; Phadke, K. A.; Strandet, M. L.; Miller, T.; Bothwell, M. S.; Ma, J.; Rotermund, K. M.; Cunningham, D. J. M.; Sreevani, J.
Germany, United States, Chile, France, United Kingdom, Canada
Abstract
We report the discovery and constrain the physical conditions of the interstellar medium of the highest-redshift millimeter-selected dusty star-forming galaxy to date, SPT-S J031132-5823.4 (hereafter SPT0311-58), at z=6.900+/- 0.002. SPT0311-58 was discovered via its 1.4 mm thermal dust continuum emission in the South Pole Telescope (SPT)-SZ survey. The spectroscopic redshift was determined through an Atacama Large Millimeter/submillimeter Array 3 mm frequency scan that detected CO(6-5), CO(7-6), and [{{C}} {{I}}](2-1), and subsequently was confirmed by detections of CO(3-2) with the Australia Telescope Compact Array and [{{C}} {{II}}] with APEX. We constrain the properties of the ISM in SPT0311-58 with a radiative transfer analysis of the dust continuum photometry and the CO and [{{C}} {{I}}] line emission. This allows us to determine the gas content without ad hoc assumptions about gas mass scaling factors. SPT0311-58 is extremely massive, with an intrinsic gas mass of {M}{gas}=3.3+/- 1.9× {10}11 {M}⊙ . Its large mass and intense star formation is very rare for a source well into the epoch of reionization.