GMVA24B-376

Pinpointing the jet launching mechanism in 3C 84 with GMVA+ALMA+GLT

Abstract

AGN jets are commonly thought to derive their power from either the ergosphere of a spinning black hole, or from an accretion disk. Recent VLBI observations have revealed that the M87 jet is launched from the vicinity of the spinning black hole and expands in a parabolic shape. Similarly, several nearby radio galaxies exhibit jet expansion into parabolic shapes within the Bondi radius, suggesting a common launching mechanism among them. In contrast, a RadioAstron space-VLBI observation found a cylindrical jet in the radio galaxy 3C 84. Notably, the observed jet width at distance of a few hundred gravitational radii is much wider than the parabolic shape expected from the black hole launching scenario. This suggests that the outer layer of the jet may originate not from the black hole, but from the accretion disk. Resolving the jet structure within ~400 gravitational radii is essential to determine the origin of the jet. Therefore, we propose a GMVA+ALMA+GLT observation to resolve the innermost region of the 3C 84 jet. If successful, this will provide crucial observational constraints on the AGN jet launching mechanisms other than the BZ mechanism.

Investigators

Name	Institution
Keiichi Asada	Academia Sinica
Jongho Park	Kyung Hee University
Sascha Trippe	Seoul National University
Minchul Kam *	Academia Sinica

* indicates the PI