Gamma-ray flares from red giant/jet interactions in AGN

Abstract

Non-blazar AGN have been recently established as a class of gamma-ray sources. M87, a nearby representative of this class, show fast TeV variability on timescales of a few days. We suggest a scenario of flare gamma-ray emission in non-blazar AGN based on a red giant interacting with the jet at the base. We solve the hydrodynamical equations that describe the evolution of the envelope of a red giant blown by the impact of the jet. If the red giant is at least slightly tidally disrupted by the supermassive black hole, enough stellar material will be blown by the jet, expanding quickly until a significant part of the jet is shocked. This process can render suitable conditions for energy dissipation and proton acceleration, which could explain the detected day-scale TeV flares from M87 via proton-proton collisions. Since the produced radiation would be unbeamed, such an events should be mostly detected from non-blazar AGN. They may be frequent phenomena, detectable in the GeV-TeV range even up to distances of $\sim 1$ Gpc for the most powerful jets. The counterparts at lower energies are expected to be not too bright.} {M87, and nearby non-blazar AGN in general, can be fast variable sources of gamma-rays through red giant/jet interactions.

8 pages, 4 figures

References in corpus (10)

• Improved Dark Energy Constraints from ~100 New CfA Supernova Type Ia Light Curves
• Stellar disruption by a supermassive black hole: is the light curve really proportional to $t^{-5/3}$?
• Magnetic acceleration of relativistic AGN jets
• Fast variability of TeV gamma-rays from the radio galaxy M 87
• The Black Hole Mass, Stellar M/L, and Dark Halo in M87
• Production of TeV gamma-radiation in the vicinity of the supermassive black hole in the giant radiogalaxy M87
• Fermi acceleration in astrophysical jets
• Formation of hard VHE gamma-ray spectra of blazars due to internal photon-photon absorption
• Variable VHE gamma-ray emission from non-blazar AGNs
• Magnetic acceleration of ultra-relativistic GRB and AGN jets

Cited by in corpus (4)

• Variable TeV emission as a manifestation of jet formation in M87?
• MAGIC observations of the giant radio galaxy M87 in a low-emission state between 2005 and 2007
• Probing the central black hole in M87 with gamma-rays
• Studies of active galactic nuclei with CTA