The blazar-like radio structure of the TeV source IC310

Дата и время публикации : 2012-01-13T15:42:27Z

Авторы публикации и институты :
Matthias Kadler
Dorit Eisenacher
Eduardo Ros
Karl Mannheim
Dominik Elsässer
Uwe Bach

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 5 pages, 3 figures (1 color); A&A, accepted
Первичная категория: astro-ph.HE

Все категории : astro-ph.HE

Краткий обзор статьи: Context. The radio galaxy IC310 in the Perseus cluster has recently been detected in the gamma-ray regime at GeV and TeV energies. The TeV emission shows time variability and an extraordinarily hard spectrum, even harder than the spectrum of the similar nearby gamma-ray emitting radio galaxy M87. Aims. High-resolution studies of the radio morphology help to constrain the geometry of the jet on sub-pc scales and to find out where the high-energy emission might come from. Methods. We analyzed May 2011 VLBA data of IC310 at a wavelength of 3.6 cm, revealing the parsec-scale radio structure of this source. We compared our findings with more information available from contemporary single-dish flux density measurements with the 100-m Effelsberg radio telescope. Results. We have detected a one-sided core-jet structure with blazar-like, beamed radio emission oriented along the same position angle as the kiloparsec scale radio structure observed in the past by connected interferometers. Doppler-boosting favoritism is consistent with an angle of theta < 38 degrees between the jet axis and the line-of-sight, i.e., very likely within the boundary dividing low-luminosity radio galaxies and BL Lac objects in unified schemes. Conclusions. The stability of the jet orientation from parsec to kiloparsec scales in IC310 argues against its classification as a headtail radio galaxy; i.e., there is no indication of an interaction with the intracluster medium that would determine the direction of the tail. IC310 seems to represent a low-luminosity FRI radio galaxy at a borderline angle to reveal its BL Lac-type central engine.

Category: Physics