Resolved CO(1-0) Emission and Gas Properties in Luminous Dusty Star-forming Galaxies at z = 2-4
Journal article, 2023
We present the results of a survey of CO(1−0) emission in 14 infrared luminous dusty star-forming galaxies (DSFGs) at 2 < z < 4 with the NSF’s Karl G. Jansky Very Large Array. All sources are detected in 12CO(1−0), with an angular resolution of ∼1″. Seven sources show extended and complex structure. We measure CO luminosities of ( μ ) L CO ( 1 − 0 ) ′ = 0.4 - 2.9 × 10 11 K km s−1 pc2, and molecular gas masses of ( μ ) M H 2 = 1.3 - 8.6 × 10 11 M ⊙, where (μ) is the magnification factor. The derived molecular gas depletion times of t dep = 40-460 Myr, cover the expected range of both normal star-forming galaxies and starbursts. Compared to the higher −J CO transitions previously observed for the same sources, we find CO temperature brightness ratios of r 32/10 = 0.4-1.4, r 43/10 = 0.4-1.7, and r 54/10 = 0.3-1.3. We find a wide range of CO spectral line energy distributions (SLEDs), in agreement with other high-z DSFGs, with the exception of three sources that are most comparable to Cloverleaf and APM08279+5255. Based on radiative transfer modeling of the CO SLEDs we determine densities of n H 2 = 0.3 − 8.5 × 10 3 cm−3 and temperatures of T K = 100-200 K. Lastly, four sources are detected in the continuum, three have radio emission consistent with their infrared-derived star formation rates, while HerBS-70E requires an additional synchrotron radiation component from an active galactic nucleus. Overall, we find that even though the sample is similarly luminous in the infrared, by tracing the CO(1−0) emission a diversity of galaxy and excitation properties are revealed, demonstrating the importance of CO(1−0) observations in combination to higher-J transitions.
Author
F. Stanley
Institut d 'Astrophysique de Paris
Institut de Radioastronomie Millimétrique (IRAM)
B. M. Jones
University of Manchester
University of Cologne
D. A. Riechers
University of Cologne
Chentao Yang
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
S. Berta
Institut de Radioastronomie Millimétrique (IRAM)
P. Cox
Institut d 'Astrophysique de Paris
Tom Bakx
Nagoya University
National Astronomical Observatory of Japan
A. Cooray
University of California
H. Dannerbauer
University of La Laguna
Instituto de Astrofísica de Canarias
S. Dye
University of Nottingham
D. H. Hughes
National Institute of Astrophysics, Optics and Electronics
R. J. Ivison
European Southern Observatory (ESO)
S. Jin
Technical University of Denmark (DTU)
Cosmic Dawn Center (DAWN)
M. Lehnert
CRAL Le Centre de Recherche Astronomique de Lyon
R. Neri
Institut de Radioastronomie Millimétrique (IRAM)
A.A. Omont
Institut d 'Astrophysique de Paris
Paul P. van der Werf
Leiden University
A. Weiss
Max Planck Society
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 945 1 24Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Other Physics Topics
DOI
10.3847/1538-4357/acb6f7