Evidence for two Lognormal States in Multi-wavelength Flux Variation of
  FSRQ PKS 1510-089
  We present a systematic characterization of multi-wavelength emission from
blazar PKS 1510-089 using well-sampled data at infrared(IR)-optical, X-ray and
$\gamma$-ray energies. The resulting flux distributions, except at X-rays, show
two distinct lognormal profiles corresponding to a high and a low flux level.
The dispersions exhibit energy dependent behavior except for the LAT
$\gamma$-ray and optical B-band. During the low level flux states, it is higher
towards the peak of the spectral energy distribution, with $\gamma$-ray being
intrinsically more variable followed by IR and then optical, consistent with
mainly being a result of varying bulk Lorentz factor. On the other hand, the
dispersions during the high state are similar in all bands expect optical
B-band, where thermal emission still dominates. The centers of distributions
are a factor of $\sim 4$ apart, consistent with anticipation from studies of
extragalactic $\gamma$-ray background with the high state showing a relatively
harder mean spectral index compared to the low state.
