Universität zu Köln

Riechers, Dominik A. ORCID: 0000-0001-9585-1462 (2025). Do Unusually Cold Starburst Galaxies Exist? A Case Study. The Astrophysical Journal, 980 (1). pp. 1-14. IOP Publishing. ISSN 0004-637X

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Abstract

[Artikel-Nr. 59] We report observations of CO( J = 9 → 8) and OH + ( N = 1 → 0) toward the four millimeter-selected lensed starburst galaxies SPT 2354−58, 0150−59, 0314−44, and 0452−50, using the Atacama Large Millimeter/submillimeter Array (ALMA) Atacama Compact Array, as part of a larger study of OH + in the early Universe. In this work, we use these observations for the main purpose of spectroscopic redshift measurements. For all sources except SPT 0452−50, we confirm the previously reported most likely redshifts, and we find typical CO and OH + properties for massive starbursts. For SPT 0452−50, we rule out the previously reported value of z = 2.0105, measuring a firm redshift of z = 5.0160 based on [O i ], [C ii ], H 2 O, and CO emission instead when adding in ancillary ALMA data. Previously, SPT 0452−50 was considered an outlier in relations between dust temperature, far-infrared luminosity, and redshift, which may have hinted at an unusually cold starburst with a dust temperature of only T dust = (21 ± 2) K. Instead, our new measurements suggest it to be among highly luminous massive dusty starbursts at z > 5, with rather typical properties within that population. We find a revised dust temperature of T dust = (76.2 ± 2.5) K, and an updated lensing-corrected far-infrared luminosity (42.5–122.5 μ m) of (2.35 − 0.08 + 0.09) × 10 13 L ⊙ , i.e., about an order of magnitude higher than previously reported. We thus do not find evidence for the existence of unusually cold starburst galaxies in the early Universe that were missed by previous selection techniques.

Item Type:	Article
Creators:	Creators Email ORCID ORCID Put Code Riechers, Dominik A. UNSPECIFIED https://orcid.org/0000-0001-9585-1462 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-797631
Identification Number:	10.3847/1538-4357/ada4ac
Journal or Publication Title:	The Astrophysical Journal
Volume:	980
Number:	1
Page Range:	pp. 1-14
Number of Pages:	1
Date:	10 February 2025
Publisher:	IOP Publishing
ISSN:	0004-637X
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institute of Physics I
Subjects:	Physics
['eprint_fieldname_oa_funders' not defined]:	Publikationsfonds UzK
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/79763