Cold Molecular Gas and Free-Free Emission from Hot, Dust-Obscured Galaxies at $z$~3

Abstract

We report on observations of redshifted CO(1-0) line emission and observed-frame $\sim$ 30GHz radio continuum emission from five ultra-luminous, mid-IR selected hot, Dust-Obscured Galaxies (Hot DOGs) at $z\gtrsim$ 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, $z\sim$ 2 redshifts, and are dominated by powerful, yet radio-quiet AGN.

15 pages, 12 figures, accepted for publication in MNRAS

References in corpus (19)

• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• The Evolution of Galaxy Structure over Cosmic Time
• The First Hyper-Luminous Infrared Galaxy Discovered by WISE
• Half of the Most Luminous Quasars May Be Obscured: Investigating the Nature of WISE-Selected Hot, Dust-Obscured Galaxies
• The far-infrared/radio correlation and radio spectral index of galaxies in the SFR-M* plane up to z 2
• The Most Luminous Galaxies Discovered by WISE
• Submillimeter Follow-up of WISE-Selected Hyperluminous Galaxies
• Molecules in galaxies
• Submillimetre observations of WISE-selected high-redshift, luminous, dusty galaxies
• An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: radio properties and the far-infrared/radio correlation
• Extending the infrared radio correlation
• Using CO line ratios to trace the physical properties of molecular clouds
• Mean and Extreme Radio Properties of Quasars and the Origin of Radio Emission
• VLA imaging of 12CO J=1-0 and free-free emission in lensed submillimetre galaxies
• Comparative Analysis of Molecular Clouds in M31, M33 and the Milky Way
• Interferometric Follow-Up of WISE Hyper-Luminous Hot, Dust-Obscured Galaxies
• The role of the most luminous, obscured AGN in galaxy assembly at z~2
• Spectral Classification and Ionized Gas Outflows in $z\sim 2$ WISE-Selected Hot Dust-Obscured Galaxies
• The AT-LESS CO(1-0) survey of submillimetre galaxies in the Extended Chandra Deep Field South: First results on cold molecular gas in galaxies at z ~ 2

Cited by in corpus (11)

• The infrared-radio correlation of star-forming galaxies is strongly M${}_{\star }$-dependent but nearly redshift-invariant since z$\sim$4
• Kinematics and Star Formation of High-Redshift Hot Dust-Obscured Quasars as Seen by ALMA
• PASSAGES: The Large Millimeter Telescope and ALMA Observations of Extremely Luminous High Redshift Galaxies Identified by the Planck
• z-GAL -- A NOEMA spectroscopic redshift survey of bright Herschel galaxies: [III] Physical properties
• Resolved CO(1-0) emission and gas properties in luminous dusty star forming galaxies at z=2-4
• COLDz: Deep 34 GHz Continuum Observations and Free-free Emission in High-redshift Star-forming Galaxies
• COLDz: Probing Cosmic Star Formation With Radio Free-free Emission
• Physical properties of hyperluminous, dust-obscured quasars at $z\sim 3$: multiwavelength Spectral Energy Distribution analysis and cold gas content revealed by ALMA
• The Host Galaxies of Radio AGN: New Views from Combining LoTSS and MaNGA Observations
• CO spectra of the ISM in the Host Galaxies of the Most Luminous WISE-Selected AGNs
• Hot Diggity Dog: Simultaneous CO and Dust Modeling of the Most Luminous WISE Hot Dust-Obscured Galaxy Unveils Extreme Molecular Gas Excitation