TY - JOUR
T1 - Resolved CO(1–0) Emission and Gas Properties in Luminous Dusty Star-forming Galaxies at z = 2–4
AU - Stanley, F.
AU - Jones, B. M.
AU - Riechers, D. A.
AU - Yang, C.
AU - Berta, S.
AU - Cox, P.
AU - Bakx, T. J. L. C.
AU - Cooray, A.
AU - Dannerbauer, H.
AU - Dye, S.
AU - Hughes, D. H.
AU - Ivison, R. J.
AU - Jin, S.
AU - Lehnert, M.
AU - Neri, R.
AU - Omont, A.
AU - van der Werf, P.
AU - Weiss, A.
PY - 2023
Y1 - 2023
N2 - 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 1011 K km s−1 pc2, and molecular gas masses of (µ)MH2 =1.3–8.6x1011 Me, 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 nH2 = 0.3 - 8.5 x103 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.
AB - 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 1011 K km s−1 pc2, and molecular gas masses of (µ)MH2 =1.3–8.6x1011 Me, 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 nH2 = 0.3 - 8.5 x103 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.
U2 - 10.3847/1538-4357/acb6f7
DO - 10.3847/1538-4357/acb6f7
M3 - Journal article
SN - 0004-637X
VL - 945
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 24
ER -