Stellar Dynamics and Star Formation Histories of z ~ 1 Radio-loud Galaxies

Barišić, Ivana and van der Wel, Arjen and Bezanson, Rachel and Pacifici, Camilla and Noeske, Kai and Muñoz-Mateos, Juan C. and Franx, Marijn and Smolčić, Vernesa and Bell, Eric F. and Brammer, Gabriel and Calhau, João and Chauké, Priscilla and van Dokkum, Pieter G. and van Houdt, Josha and Gallazzi, Anna and Labbé, 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 ~ 1 Radio-loud Galaxies. Astrophysical Journal, 847 (1). pp. 72-9. ISSN 0004-637X

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We investigate the stellar kinematics and stellar populations of 58 radio-loud galaxies of intermediate luminosities (L 3 GHz > 1023 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 ~ 1 radio galaxies. We find that z ~ 1 radio-loud active galactic nucleus (AGN) occur exclusively in predominantly old galaxies with high velocity dispersions: σ * > 175 km s−1, corresponding to black hole masses in excess of 108 M⊙. Furthermore, we confirm that at a fixed stellar mass the fraction of radio-loud AGN at z ~ 1 is five to 10 times higher than in the local universe, suggesting that quiescent, massive galaxies at z ~ 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 ~ 1.

Item Type: Article
Keywords: galaxies, evolution – galaxies, fundamental parameters – galaxies, high-redshift – galaxies, jets – galaxies, star formation
Date: 2017
Subjects: NATURAL SCIENCES > Physics > Astronomy and Astrophysics
Additional Information: © 2017. The American Astronomical Society. Received 2017 June 1; revised 2017 August 2; accepted 2017 August 11; published 2017 September 21. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement 683184). This work was based on observations made with ESO Telescopes at the La Silla or Paranal Observatories under programme ID 194.A-2005. V.S. acknowledges support from the European Union’s Seventh Frame-work program under grant agreement 337595 (ERC Starting Grant, “CoSMass”).
Divisions: Faculty of Science > Department of Physics
Publisher: IOP Publishing
Depositing User: Gordana Stubičan Ladešić
Date Deposited: 08 Nov 2017 10:39
Last Modified: 08 Nov 2017 10:39

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