TY - JOUR
T1 - Molecular Line Observations in Two Dusty Star-forming Galaxies at z = 6.9
AU - Jarugula, Sreevani
AU - Vieira, Joaquin D.
AU - Weiss, Axel
AU - Spilker, Justin S.
AU - Aravena, Manuel
AU - Archipley, Melanie
AU - Béthermin, Matthieu
AU - C. Chapman, Scott
AU - Dong, Chenxing
AU - Greve, Thomas R.
AU - Harrington, Kevin
AU - Hayward, Christopher C.
AU - Hezaveh, Yashar
AU - Hill, Ryley
AU - Litke, Katrina C.
AU - Malkan, Matthew A.
AU - Marrone, Daniel P.
AU - Narayanan, Desika
AU - Phadke, Kedar A.
AU - Reuter, Cassie
AU - Rotermund, Kaja M.
PY - 2021/11/3
Y1 - 2021/11/3
N2 - SPT0311-58 is the most massive infrared luminous system discovered so far during the Epoch of Reionization (EoR). In this paper, we present a detailed analysis of the molecular interstellar medium at z = 6.9, through high resolution observations of the CO(6-5), CO(7-6), CO(10-9), [C I](2-1), and p-H2O(21,1 -20,2) lines and dust continuum emissions with the Atacama Large Millimeter/submillimeter Array. The system consists of a pair of intensely star-forming, gravitationally lensed galaxies (labeled West and East). The intrinsic far-infrared luminosity is (16 ± 4) × 1012 Le in West and (27 ± 4) × 1011 Le in East. We model the dust, CO, and [C I] using non-local thermodynamic equilibrium radiative transfer models and estimate the intrinsic gas mass to be (5.4 ± 3.4) × 1011Me in West and (3.1 ± 2.7) × 1010Me in East. We find that the CO spectral line energy distribution in West and East are typical of high-redshift submillimeter galaxies (SMGs). The CO-to-H2 conversion factor (αCO) and the gas depletion timescales estimated from the model are consistent with the high-redshift SMGs in the literature within the uncertainties. We find no evidence of evolution of depletion time with redshift in SMGs at z > 3. This is the most detailed study of molecular gas content of a galaxy in the EoR to date, with the most distant detection of H2O in a galaxy without any evidence for active galactic nuclei in the literature.
AB - SPT0311-58 is the most massive infrared luminous system discovered so far during the Epoch of Reionization (EoR). In this paper, we present a detailed analysis of the molecular interstellar medium at z = 6.9, through high resolution observations of the CO(6-5), CO(7-6), CO(10-9), [C I](2-1), and p-H2O(21,1 -20,2) lines and dust continuum emissions with the Atacama Large Millimeter/submillimeter Array. The system consists of a pair of intensely star-forming, gravitationally lensed galaxies (labeled West and East). The intrinsic far-infrared luminosity is (16 ± 4) × 1012 Le in West and (27 ± 4) × 1011 Le in East. We model the dust, CO, and [C I] using non-local thermodynamic equilibrium radiative transfer models and estimate the intrinsic gas mass to be (5.4 ± 3.4) × 1011Me in West and (3.1 ± 2.7) × 1010Me in East. We find that the CO spectral line energy distribution in West and East are typical of high-redshift submillimeter galaxies (SMGs). The CO-to-H2 conversion factor (αCO) and the gas depletion timescales estimated from the model are consistent with the high-redshift SMGs in the literature within the uncertainties. We find no evidence of evolution of depletion time with redshift in SMGs at z > 3. This is the most detailed study of molecular gas content of a galaxy in the EoR to date, with the most distant detection of H2O in a galaxy without any evidence for active galactic nuclei in the literature.
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U2 - 10.3847/1538-4357/ac21db
DO - 10.3847/1538-4357/ac21db
M3 - Article
SN - 0004-637X
VL - 921
SP - 97
JO - The Astrophysical journal
JF - The Astrophysical journal
IS - 1
M1 - 97
ER -