GMVA20B-204

First subparsec-scale imaging of the new TeV gamma-ray radio galaxy 3C 264

Abstract

Since the first detection of astrophysical gamma-rays, numerous active galactic nuclei have been detected up to extreme TeV photon energies. While the vast majority of them, blazars, have strong jets sharply aligned to the observers and their TeV emission is well explained by the strong Doppler boosting, a new class of TeV sources, radio galaxies, raises a serious challenge to this interpretation because of their misaligned jets. 3C264 is the sixth newly discovered TeV-emitting, FR I radio galaxy with a uniquely collimated and edge-brightened pc-scale jet, similar to another TeV radio galaxy M87, but has not been imaged on subparsec scales or <1000 Schwarzschild radii (Rs). Here we propose the first deep and high resolution imaging of 3C264 at 86 GHz with GMVA+ALMA, resolving the jet base region, a possible site of TeV production, down to 50uas (500Rs) scales. The new image will allow us to: (1) understand the beaming, collimation, and stratification of the outflow, and (2) pin down the magnetization of the compact core. This will sharply constrain possible TeV emission mechanisms in 3C264, and also enable a direct comparison of the physics to that in the similar TeV source M87.

Investigators

Name	Institution
Jongho Park	Kyung Hee University
Shoko Koyama	National Astronomical Observatory of Japan ; Academia Sinica
Masanori Nakamura	Academia Sinica; National Institute of Technology, Hachinohe College
Keiichi Asada	Academia Sinica
Eduardo Ros	Max-Planck-Institut für Radioastronomie; València, Universitat de
Yuzhu Cui	Zhejiang Lab
Kazuhiro Hada	Istituto Nazionale di Astrofisica; National Astronomical Observatory of Japan
Tony Zensus	National Radio Astronomy Observatory; Max-Planck-Institut für Radioastronomie
Biagina Boccardi	Max-Planck-Institut für Radioastronomie
Rocco Lico	Istituto Nazionale di Astrofisica; Max-Planck-Institut für Radioastronomie; Andalucía, Instituto de Astrofísica de
Thomas Krichbaum	Max-Planck-Institut für Radioastronomie
Jae-Young Kim *	Max-Planck-Institut für Radioastronomie; Kyungpook National University
GBT Operator	Green Bank Observatory

* indicates the PI