Cold Molecular Gas and Free-Free Emission from Hot, Dust-Obscured Galaxies at $z$~3
| Autor: | Penney, J. I., Blain, A. W., Assef, R. J., Diaz-Santos, T., González-López, J. J., Tsai, C. -W., Aravena, M., Eisenhardt, P. R. M., Jones, S. F., Jun, H. D., Kim, M., Stern, D., Wu, J. |
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| Rok vydání: | 2020 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/staa1582 |
| Popis: | We report on observations of redshifted CO(1-0) line emission and observed-frame $\rm\sim$ 30GHz radio continuum emission from five ultra-luminous, mid-IR selected hot, Dust-Obscured Galaxies (Hot DOGs) at $z\rm\gtrsim$ 3 using the Karl G. Jansky Very Large Array. We detect CO(1-0) line emission in all five Hot DOGs, with one of them at high signal to noise. We analyse FIR-radio spectral energy distributions, including dust, free-free and synchrotron emission for the galaxies. We find that most of the 115 GHz rest-frame continuum is mostly due to synchrotron or free-free emission, with only a potentially small contribution from thermal emission. We see a deficit in the rest-frame 115 GHz continuum emission compared to dusty star-forming galaxies (DSFGs) and sub-millimetre galaxies (SMGs) at high redshift, suggesting that Hot DOGs do not have similar cold gas reserves compared with star-forming galaxies. One target, W2305-0039, is detected in the FIRST 1.4 GHz survey, and is likely to possess compact radio jets. We compare to the FIR-radio correlation, and find that at least half of the Hot DOGs in our sample are radio-quiet with respect to normal galaxies. These findings suggest that Hot DOGs have comparably less cold molecular gas than star-forming galaxies at lower, $z\rm\sim$ 2 redshifts, and are dominated by powerful, yet radio-quiet AGN. Comment: 15 pages, 12 figures, accepted for publication in MNRAS |
| Databáze: | arXiv |
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