Radio and gamma-ray properties of extragalactic jets from the TANAMI sample

¹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
e-mail: boeck.moritz@gmail.com
² Dr. Karl-Remeis-Sternwarte, Astronomisches Institut der Universität Erlangen-Nürnberg, and Erlangen Centre for Astroparticle Physics, Sternwartstraße 7, 96049 Bamberg, Germany
³ Lehrstuhl für Astronomie, Universität Würzburg, Emil-Fischer Str. 31, 97074 Würzburg, Germany
e-mail: matthias.kadler@astro.uni-wuerzburg.de
⁴ Department of Astrophysics, Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, PO Box 9010, 6500 GL Nijmegen, The Netherlands
⁵ INFN/University of Perugia, 06123 Perugia, Italy
⁶ NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771, USA
e-mail: roopesh.ojha@nasa.gov
⁷ Institute for Astrophysics & Computational Sciences, Catholic University of America, Washington, DC 20064, USA
⁸ CRESST/University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
⁹ Istituto Nazionale di Fisica Nucleare, Sezione di Padova, 35131 Padova, Italy
¹⁰ Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova, 35131 Padova, Italy
¹¹ University of Washington, Seattle, WA 98195, USA
¹² Agenzia Spaziale Italiana (ASI) Science Data Center, 00133 Roma, Italy
¹³ School of Mathematics & Physics, University of Tasmania, Private Bag 37, Hobart, 7001 Tasmania, Australia
¹⁴ CSIRO Astronomy and Space Science, ATNF, PO Box 76 Epping, NSW 1710, Australia
¹⁵ Bundesamt für Kartographie und Geodäsie, 93444 Bad Kötzting, Germany
¹⁶ CSIRO Astronomy and Space Science, Canberra Deep Space Communications Complex, PO Box 1035, Tuggeranong, ACT 2901, Australia
¹⁷ Hartebeesthoek Radio Astronomy Observatory, 1740 Krugersdorp, South Africa
¹⁸ Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907, USA
¹⁹ Centre d’Études Nucléaires de Bordeaux Gradignan, IN2P3/CNRS, Université Bordeaux 1, BP120, 33175 Gradignan Cedex, France
²⁰ Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
²¹ Nordic Optical Telescope, Apartado 474, 38700 Santa Cruz de La Palma, Santa Cruz de Tenerife, Spain
²² Observatori Astronòmic, Universitat de València, Parc Científic, C. Catedrático José Beltrán 2, 46980 Paterna, València, Spain
²³ Departament d’Astronomia i Astrofísica, Universitat de València, C. Dr. Moliner 50, 46100 Burjassot, València, Spain
²⁴ Department of Physics and Astronomy, University of New Mexico, Albuquerque NM, 87131, USA
²⁵ Adjunct Astronomer at the National Radio Astronomy Observatory, USA
²⁶ Centre for Astrophysics and Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, Australia

Received: 7 August 2014
Accepted: 2 November 2015

Abstract

The TANAMI program has been observing parsec-scale radio jets of southern (declination south of − 30°) γ-ray bright AGN, simultaneously with Fermi/LAT monitoring of their γ-ray emission, via high-resolution radio imaging with Very Long Baseline Interferometry techniques. We present the radio and γ-rayproperties of the TANAMI sources based on one year of contemporaneous TANAMI and Fermi/LAT data. A large fraction (72%) of the TANAMI sample can be associated with bright γ-ray sources for this time range. Association rates differ for different optical classes with all BL Lacs, 76% of quasars, and just 17% of galaxies detected by the LAT. Upper limits were established on the γ-ray flux from TANAMI sources not detected by LAT. This analysis led to the identification of three new Fermi sources whose detection was later confirmed. The γ-ray and radio luminosities are related by L_γ ∝ L_r^0.89±0.04. The brightness temperatures of the radio cores increase with the average γ-ray luminosity and the presence of brightness temperatures above the inverse Compton limit implies strong Doppler boosting in those sources. The undetected sources have lower γ/radio luminosity ratios and lower contemporaneous brightness temperatures. Unless the Fermi/LAT-undetected blazars are much γ-ray-fainter than the Fermi/LAT-detected sources, their γ-ray luminosity should not be significantly lower than the upper limits calculated here.