Gamma-ray emission in radio galaxies under the VLBI scope ...

• Main Authors: Angioni, R., Ros, E., Kadler, M., Ojha, R., Müller, C., Edwards, P. G., Burd, P. R., Carpenter, B., Dutka, M. S., Gulyaev, S., Hase, H., Horiuchi, S., Krauß, F., Lovell, J. E. J., Natusch, T., Phillips, C., Plötz, C., Quick, J. F. H., Rösch, F., Schulz, R., Stevens, J., Tzioumis, A. K., Weston, S., Wilms, J, Zensus, J. A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: EDP Sciences 2019
• Subjects: galaxies; active; nuclei; jets – γ rays; Austral; New Zealand; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.13016/m219md-nrmb; http://mdsoar.org/handle/11603/15001

Aims. In the framework of the multi-wavelength and very long baseline interferometry (VLBI) monitoring program TANAMI (Tracking Active Nuclei with Austral Milliarcsecond Interferometry), we study the evolution of the parsec-scale radio emission in radio galaxies in the southern hemisphere and their relationship to the γ-ray properties of the sources. Our study investigates systematically, for the first time, the relationship between the two energy regimes in radio galaxies. In this first paper, we focus on Fermi-LAT-detected sources. Methods. The TANAMI program monitors a large sample of radio-loud AGN at 8.4 GHz and 22.3 GHz with the Australian long baseline array (LBA) and associated telescopes in Antarctica, Chile, New Zealand and South Africa. We performed a kinematic analysis for five γ-ray detected radio galaxies using multi-epoch 8.4 GHz VLBI images, deriving limits on intrinsic jet parameters such as speed and viewing angle. We analyzed 103 months of Fermi-LAT data in order to study possible ...