COLA. III. RADIO DETECTION OF ACTIVE GALACTIC NUCLEUS IN COMPACT MODERATE LUMINOSITY INFRARED GALAXIES
Journal article, 2010

We present results from 4.8 GHz Very Large Array (VLA) and global very long baseline interferometry (VLBI) observations of the northern half of the moderate FIR luminosity (median L-IR = 10(11.01) L-circle dot) COLA sample of star-forming galaxies. VLBI sources are detected in a high fraction (20/90) of the galaxies observed. The radio luminosities of these cores (similar to 10(21) W Hz(-1)) are too large to be explained by radio supernovae or supernova remnants and we argue that they are instead powered by active galactic nuclei (AGNs). These sub-parsec scale radio cores are preferentially detected toward galaxies whose VLA maps show bright 100-500 parsec scale nuclear radio components. Since these latter structures tightly follow the FIR to radio-continuum correlation for star formation, we conclude that the AGN-powered VLBI sources are associated with compact nuclear starburst environments. The implications for possible starburst-AGN connections are discussed. The detected VLBI sources have a relatively narrow range of radio luminosity consistent with models in which intense compact Eddington-limited starbursts regulate the gas supply onto a central supermassive black hole. The high incidence of AGN radio cores in compact starbursts suggests little or no delay between the starburst phase and the onset of AGN activity.

infrared: galaxies

starburst-agn connection

black-hole

emission

host

galaxies

galaxies: active

supernova-remnants

sample

continuum: galaxies

line

radio

arp-220

classification

galaxies: starburst

spectra

Author

Rodrigo Parra Barraza

Chalmers, Department of Radio and Space Science, Radio Astronomy and Astrophysics

John Conway

Chalmers, Department of Radio and Space Science, Radio Astronomy and Astrophysics

Susanne Aalto

Chalmers, Department of Radio and Space Science, Radio Astronomy and Astrophysics

P. Appleton

California Institute of Technology (Caltech)

R. P. Norris

Australia Telescope National Facility

Y. Pihlstrom

University of New Mexico

National Radio Astronomy Observatory

L. J. Kewley

University of Hawaii

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 720 1 555-568

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.1088/0004-637X/720/1/555

More information

Latest update

4/13/2018