1. Resolved CO(1–0) Emission and Gas Properties in Luminous Dusty Star-forming Galaxies at z = 2–4.
- Author
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Stanley, F., Jones, B. M., Riechers, D. A., Yang, C., Berta, S., Cox, P., Bakx, T. J. L. C., Cooray, A., Dannerbauer, H., Dye, S., Hughes, D. H., Ivison, R. J., Jin, S., Lehnert, M., Neri, R., Omont, A., van der Werf, P., and Weiss, A.
- Subjects
STARBURSTS ,GALAXIES ,SPECTRAL energy distribution ,ACTIVE galactic nuclei ,SYNCHROTRON radiation ,STAR formation - Abstract
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
12 CO(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 tdep = 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 r32/10 = 0.4–1.4, r43/10 = 0.4–1.7, and r54/10 = 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 TK = 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. [ABSTRACT FROM AUTHOR]- Published
- 2023
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