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 Cologne

University of Manchester

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 J.L.C. Bakx

Nagoya University

National Astronomical Observatory of Japan

A. Cooray

University of California at Irvine (UCI)

H. Dannerbauer

Instituto de Astrofísica de Canarias

University of La Laguna

S. Dye

University of Nottingham

D. H. Hughes

National Institute of Astrophysics, Optics and Electronics

R. J. Ivison

European Southern Observatory (ESO)

S. Jin

Cosmic Dawn Center (DAWN)

Technical University of Denmark (DTU)

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 24

Subject Categories

Astronomy, Astrophysics and Cosmology

Atom and Molecular Physics and Optics

Other Physics Topics

DOI

10.3847/1538-4357/acb6f7

More information

Latest update

3/17/2023