Abstract:
Here we report our recent discoveries of Quasi-Periodic
Oscillations (QPOs) in blazars time series data in X-ray and optical elec-
tromagnetic bands. Any such detection can give important clues of the
location and nature of the processes of emission mechanism. In the case
of radio-quiet AGN, the detected QPOs are very likely to be associated
with the accretion disk. But in the case of blazars, it may be associated
with jets in the high and outburst states, and in the low-state, it is prob-
ably associated with the accretion disk. In this brief review, I summarize
the recent QPO detections in blazars. There is one strong evidence of
QPO detection in XMM–Newton time series data of narrow line Seyfert 1
galaxy RE J1034 + 396 about which we will also discuss briefly.
