Statistical analysis of variability properties of the Kepler blazar W2R
  1926+42
  We analyzed Kepler light curves of the blazar W2R 1926+42 that provided
nearly continuous coverage from quarter 11 through quarter 17 (589 days between
2011 and 2013) and examined some of their flux variability properties. We
investigate the possibility that the light curve is dominated by a large number
of individual flares and adopt exponential rise and decay models to investigate
the symmetry properties of flares. We found that those variations of W2R
1926+42 are predominantly asymmetric with weak tendencies toward positive
asymmetry (rapid rise and slow decay). The durations (D) and the amplitudes
(F0) of flares can be fit with log-normal distributions. The energy (E) of each
flare is also estimated for the first time. There are positive correlations
between logD and logE with a slope of 1.36, and between logF0 and logE with a
slope of 1.12. Lomb-Scargle periodograms are used to estimate the power
spectral density (PSD) shape. It is well described by a power law with an index
ranging between -1.1 and -1.5. The sizes of the emission regions, R, are
estimated to be in the range of 1.1*10^15 cm - 6.6*10^16 cm. The flare
asymmetry is difficult to explain by a light travel time effect but may be
caused by differences between the timescales for acceleration and dissipation
of high-energy particles in the relativistic jet. A jet-in-jet model also could
produce the observed log-normal distributions.
