On the Origin of Rapid Flares in TeV Blazars

TL;DR

This paper proposes that rapid TeV blazar flares result from radiative deceleration of blobs in jets, with local dissipation and background radiation enabling high-energy photon escape, challenging previous Doppler factor assumptions.

Contribution

It introduces a model where radiative deceleration of blobs explains rapid TeV flares, aligning with observed jet powers and allowing gamma-ray escape.

Findings

Radiative deceleration can produce rapid TeV flares.

Background radiation field of 10^{41}-10^{42} erg/s enables deceleration and gamma-ray escape.

Jet power estimates are consistent with the deceleration model.

Abstract

The rapid variability of the VHE emission reported for some TeV blazars implies Doppler factors well in excess of those inferred from superluminal motions and unification schemes. We propose that those extreme flares may result from radiative deceleration of blobs on scales where local dissipation occurs. The minimum jet power estimated from the resolved synchrotron emission on VLBI scales appears to be consistent with this model. It is shown that if the energy distribution of nonthermal electrons accelerated locally in the blob is reasonably flat, then a background radiation field having a luminosity in the range 10$^{41}-10^{42}$ erg s$^{-1}$ can give rise to a substantial deceleration of the blob, but still be transparent enough to allow the TeV $\gamma$-rays thereby produced to escape the system.