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ALMA Imaging of the CO(7-6) Line Emission in the Submillimeter Galaxy LESS 073 at redshift 4.755$^\star$

Authors :
Zhao, Yinghe
Lu, Nanyao
Díaz-Santos, Tanio
Gao, Yu
Xu, C. Kevin
Charmandaris, Vassilis
Inami, Hanae
Rigopoulou, Dimitra
Sanders, David B.
Huang, Jiasheng
Wang, Zhong
Source :
ApJ, 892, 145 (2020)
Publication Year :
2020

Abstract

In this paper we present our imaging observations on the CO(7-6) line and its underlying continuum emission of the young submillimeter galaxy LESS 073 at redshift 4.755, using the Atacama Large Millimeter/submillimeter Array (ALMA). At the achieved resolution of $\sim$$1^{\prime\prime}.2\times0^{\prime\prime}.9$ ($8\times6$~kpc$^2$), the CO(7-6) emission is largely unresolved (with a deconvolved size of $1^{\prime\prime}.1(\pm0^{\prime\prime}.5) \times 0^{\prime\prime}.9(\pm0^{\prime\prime}.8)$), and the continuum emission is totally unresolved. The CO(7-6) line emission has an integrated flux of $0.86\pm0.08$~Jy km/s, and a line width of $343\pm40$ km/s. The continuum emission has a flux density of 0.51 mJy. By fitting the observed far-infrared (FIR) spectral energy distribution of LESS 073 with a single-temperature modified blackbody function, we obtained a dust temperature $T_{\rm dust}=57.6\pm3.5$ K, 60-to-100 $\mu$m flux density ratio $f_{60}/f_{100}=0.86\pm0.08$, and total infrared luminosity $L_{\rm IR}=(5.8\pm0.9) \times 10^{12}~L_\odot$. The SED-fit-based $f_{60}/f_{100}$ is consistent with those estimated from various line ratios as advocated by our earlier work, indicating that those proposed line-ratio-based method can be used to practically derive $f_{60}/f_{100}$ for high-$z$ sources. The total molecular gas mass of LESS 073 is $(3.3\pm1.7) \times10^{10}~M_\odot$, and the inferred gas depletion time is about 43 Myr.<br />Comment: 8 pages, 6 figures, accepted for publication in ApJ

Details

Database :
arXiv
Journal :
ApJ, 892, 145 (2020)
Publication Type :
Report
Accession number :
edsarx.2002.04816
Document Type :
Working Paper
Full Text :
https://doi.org/10.3847/1538-4357/ab75eb