Tachyonic -ray cascades from BL Lacertae objects

Department of Physics, Hiroshima University - 1-3-1 Kagami-yama, Higashi-Hiroshima 739-8526, Japan

Corresponding author: tom@geminga.org

Received: 28 November 2008
Accepted: 15 December 2008

Abstract

Evidence for superluminal radiation from TeV blazars is pointed out. Spectral fits of the BL Lacertae objects W Comae, 1ES 2344+514, PG 1553+113, and 1ES 0806+524 are performed with tachyonic γ-ray cascades generated by the thermal electron plasma in the galactic nuclei. The transversal and longitudinal radiation components as well as the thermodynamic parameters of the ultra-relativistic electron populations are extracted from the spectral maps based on EGRET, VERITAS, MAGIC, and HESS flux data. An extended spectral plateau typical for tachyonic γ-ray spectra emerges in the MeV and low GeV range, terminating in exponential decay without a power law crossover. Thermal tachyonic cascade spectra are also predicted for Fermi blazars. By comparing to other TeV γ-ray sources such as Galactic supernova remnants and pulsar wind nebulae as well as active galactic nuclei, the curvature in the high-energy spectral slopes of BL Lacertae objects is shown to be intrinsic, i.e. uncorrelated with distance.