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Title: A dense, solar metallicity ISM in the z = 4.2 dusty star-forming galaxy SPT 0418−47
We present a study of six far-infrared fine structure lines in the z = 4.225 lensed dusty star-forming galaxy SPT 0418−47 to probe the physical conditions of its interstellar medium (ISM). In particular, we report Atacama Pathfinder EXperiment (APEX) detections of the [OI] 145 μ m and [OIII] 88 μ m lines and Atacama Compact Array (ACA) detections of the [NII] 122 and 205 μ m lines. The [OI] 145 μ m/[CII] 158 μ m line ratio is ∼5× higher compared to the average of local galaxies. We interpret this as evidence that the ISM is dominated by photo-dissociation regions with high gas densities. The line ratios, and in particular those of [OIII] 88 μ m and [NII] 122 μ m imply that the ISM in SPT 0418−47 is already chemically enriched to nearly solar metallicity. While the strong gravitational amplification was required to detect these lines with APEX, larger samples can be observed with the Atacama Large Millimeter/submillimeter Array (ALMA), and should allow observers to determine if the dense, solar metallicity ISM is common among these highly star-forming galaxies.  more » « less
Award ID(s):
1852617 1248097 1716229
PAR ID:
10166307
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Astronomy & Astrophysics
Volume:
631
ISSN:
0004-6361
Page Range / eLocation ID:
A167
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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