| Abstract: | Very high energy (VHE, $E>$100 GeV) $gamma$-ray flaring activity of the
high-frequency peaked BL Lac object pg has been detected by the hess
telescopes. The flux of the source increased by a factor of 3 during the nights
of 2012 April 26 and 27 with respect to the archival measurements with hint of
intra-night variability. No counterpart of this event has been detected in the
fla data. This pattern is consistent with VHE $gamma$ ray flaring being
caused by the injection of ultrarelativistic particles, emitting $gamma$ rays
at the highest energies. The dataset offers a unique opportunity to constrain
the redshift of this source at estz using a novel method based on Bayesian
statistics. The indication of intra-night variability is used to introduce a
novel method to probe for a possible Lorentz Invariance Violation (LIV), and to
set limits on the energy scale at which Quantum Gravity (QG) effects causing
LIV may arise. For the subluminal case, the derived limits are $ extrm{E}_{
m
QG,1}>4.10 imes 10^{17}$ GeV and $ extrm{E}_{
m QG,2}>2.10 imes 10^{10}$
GeV for linear and quadratic LIV effects, respectively. |
REGISTER
Did you like this article? 
