Cold molecular gas and free-free emission from hot, dust-obscured galaxies at z similar to 3
Artikel i vetenskaplig tidskrift, 2020

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

radio lines: galaxies

galaxies: evolution

galaxies: active



University Of Leicester

A. W. Blain

University Of Leicester

R. J. Assef

Universidad Diego Portales

T. Diaz-Santos

Chinese Academy of Sciences

Idryma Technologias kai Erevnas (FORTH)

Universidad Diego Portales

J. Gonzalez-Lopez

Carnegie Institution for Science

Universidad Diego Portales

C-W Tsai

Chinese Academy of Sciences

M. Aravena

Universidad Diego Portales

P. R. M. Eisenhardt

California Institute of Technology (Caltech)

Suzy Jones

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

H. D. Jun

Korea Institute for Advanced Study

M. Kim

Kyungpook National University

D. Stern

California Institute of Technology (Caltech)

J. Wu

Chinese Academy of Sciences

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 496 2 1565-1578


Analytisk kemi

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik



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