https://doi.org/10.1051/epjconf/20136106004
A sensitive study of the peculiar jet structure HST-1 in M87
1 Instituto de Astrofísica de Andalucía, CSIC, Apartado 3004, 18080 Granada, Spain
2 INAF Istituto di Radioastronomia, via Gobetti 101, 40129 Bologna, Italy
3 Dipartimento di Astronomia, via Ranzani 1, 40127 Bologna, Italy
4 Department of Astronomical Science, The Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan
5 National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo, 181-8588, Japan
6 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
7 Departament d’Astronomia i Astrofisica, Universitat de València, Dr. Moliner 50, 46100 Burjassot, Valencia, Spain
a e-mail: casadio@iaa.es
Published online: 9 December 2013
To obtain a better understanding of the location and mechanisms for the production of the gamma-ray emission in jets of AGN we present a detailed study of the HST-1 structure, 0.8 arcsec downstream the jet ofM87, previously identified as a possible candidate for TeV emission. HST-1 shows a very peculiar structure with superluminal as well as possible stationary sub-components, and appears to be located in the transition from a parabolic to a conical jet shape, presumably leading to the formation of a recollimation shock. This scenario is supported by our new RHD simulations in which the interaction of a moving component with are collimation shock leads to the appearance of a new superluminal component. To discern whether HST-1 is produced by a recollimation shock or some other MHD instability, we present new polarimetric 2.2 and 5 GHz VLBA, as well as 15, 22 and 43 GHz JVLA observations obtained between November 2012 and March 2013.
© Owned by the authors, published by EDP Sciences, 2013
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
