Barisic, Ivana and van der Wel, Arjen and Bezanson, Rachel and Pacifici, Camilla and Noeske, Kai and Munoz-Mateos, Juan C. and Franx, Marijn and Smolcic, Vernesa and Bell, Eric F. and Brammer, Gabriel and Calhau, Joao and Chauke, Priscilla and van Dokkum, Pieter G. and van Houdt, Josha and Gallazzi, Anna and Labbe, Ivo and Maseda, Michael V. and Muzzin, Adam and Sobral, David and Straatman, Caroline and Wu, Po-Feng (2017) Stellar Dynamics and Star Formation Histories of z similar to 1 Radio-loud Galaxies. The Astrophysical Journal, 847 (1): 72. ISSN 0004-637X
1708.08461v1.pdf - Accepted Version
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Abstract
We investigate the stellar kinematics and stellar populations of 58 radio-loud galaxies of intermediate luminosities (L-3 GHz > 10(23) W Hz(-1)) at 0.6 <z <1. This sample is constructed by cross-matching galaxies from the deep VLT/VIMOS LEGA-C spectroscopic survey with the VLA 3 GHz data set. The LEGA-C continuum spectra reveal for the first time stellar velocity dispersions and age indicators of z similar to 1 radio galaxies. We find that z similar to 1 radio-loud active galactic nucleus (AGN) occur exclusively in predominantly old galaxies with high velocity dispersions: sigma(*) > 175 kms(-1), corresponding to black hole masses in excess of 10(8) M-circle dot. Furthermore, we confirm that at a fixed stellar mass the fraction of radio-loud AGN at z similar to 1 is five to 10 times higher than in the local universe, suggesting that quiescent, massive galaxies at z similar to 1 switch on as radio AGN on average once every Gyr. Our results strengthen the existing evidence for a link between high black hole masses, radio loudness, and quiescence at z similar to 1.