Volume 610, February 2018
|Number of page(s)||18|
|Published online||07 February 2018|
TANAMI: Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry⋆
II. Additional sources
1 Department of Astrophysics/IMAPP, Radboud University Nijmegen, PO Box 9010, 6500 GL Nijmegen, The Netherlands
2 Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
3 Dr. Remeis-Sternwarte & ECAP, Universität Erlangen-Nürnberg, Sternwartstraße 7, 96049 Bamberg, Germany
4 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
5 NASA, Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771, USA
6 CRESST/University of Maryland Baltimore County, Baltimore, MD 21250, USA
7 Catholic University of America, Washington, DC 20064, USA
8 ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo, The Netherlands
9 Joint Institute for VLBI ERIC (JIVE), Postbus 2, 7990 AA Dwingeloo, The Netherlands
10 Wyle Science, Technology and Engineering Group, Greenbelt, MD 20771, USA
11 ECAP, Universität Erlangen-Nürnberg, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
12 CSIRO Astronomy and Space Science, ATNF, PO Box 76 Epping, NSW 1710, Australia
13 Observatori Astronòmic, Universitat de València, 46980 Paterna, València, Spain
14 Dept. d’Astronomia i Astrofísica, Universitat de València, 46100 Burjassot, València, Spain
15 Institute for Radio Astronomy & Space Research, AUT University, 1010 Auckland, New Zealand
16 Bundesamt für Kartographie und Geodäsie, 93444 Bad Kötzting, Germany
17 CSIRO Astronomy and Space Science, Canberra Deep Space Communications Complex, PO Box 1035, Tuggeranong, ACT 2901, Australia
18 GRAPPA & Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
19 School of Mathematics & Physics, University of Tasmania, Private Bag 37, Hobart, 7001 Tasmania, Australia
20 INAF/IAPS, via Fosso del Cavaliere 100, 00133 Roma, Italy
21 Nordic Optical Telescope Apartado 474, 38700 Santa Cruz de La Palma Santa Cruz de Tenerife, Spain
22 Hartebeesthoek Radio Astronomy Observatory, PO Box 443, 1740 Krugersdorp, South Africa
23 International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102, Australia
24 INAF, Istituto di Radio Astronomia, via Piero Gobetti, 41029 Bologna, Italy
Received: 27 June 2017
Accepted: 4 September 2017
Context. TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of − 30° declination including high-resolution very long baseline interferometry (VLBI) imaging, radio, optical/UV, X-ray, and γ-ray studies. We have previously published first-epoch8.4 GHz VLBI images of the parsec-scale structure of the initial sample. In this paper, we present images of 39 additional sources. The full sample comprises most of the radio- and γ-ray brightest AGN in the southern quarter of the sky, overlapping with the region from which high-energy (> 100 TeV) neutrino events have been found.
Aims. We characterize the parsec-scale radio properties of the jets and compare them with the quasi-simultaneous Fermi/LAT γ-ray data. Furthermore, we study the jet properties of sources which are in positional coincidence with high-energy neutrino events compared to the full sample. We test the positional agreement of high-energy neutrino events with various AGN samples.
Methods. TANAMI VLBI observations at 8.4 GHz are made with southern hemisphere radio telescopes located in Australia, Antarctica, Chile, New Zealand, and South Africa.
Results. Our observations yield the first images of many jets below − 30° declination at milliarcsecond resolution. We find that γ-ray loud TANAMI sources tend to be more compact on parsec-scales and have higher core brightness temperatures than γ-ray faint jets, indicating higher Doppler factors. No significant structural difference is found between sources in positional coincidence with high-energy neutrino events and other TANAMI jets. The 22 γ-ray brightest AGN in the TANAMI sky show only a weak positional agreement with high-energy neutrinos demonstrating that the > 100 TeV IceCube signal is not simply dominated by a small number of the γ-ray brightest blazars. Instead, a larger number of sources have to contribute to the signal with each individual source having only a small Poisson probability for producing an event in multi-year integrations of current neutrino detectors.
Key words: galaxies: active / galaxies: jets / galaxies: nuclei / radio continuum: galaxies / techniques: high angular resolution / neutrinos
The cleaned VLBI images displayed in Figs. 1, 2 and A.1 (FITS files) are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (188.8.131.52) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A1
© ESO, 2018
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