Ongoing rotation of the optical polarization plane for the blazar PKS 1510-089
ATel #9402; D. Blinov, I. Kyritsis, A. Lalakos (Univ. of Crete, Greece) on behalf of the RoboPol collaboration
on 23 Aug 2016; 21:02 UT
Credential Certification: Dmitriy Blinov (firstname.lastname@example.org)
Subjects: Optical, Gamma Ray, Black Hole, Blazar
Our R-band polarimetric monitoring of the blazar PKS1510-089 (RA=15h12m50.5s, DEC=-09d05m59.8s, J2000) with the RoboPol instrument shows rotation of the polarization plane. Starting from August, 5, the polarization angle has been performing a monotonic rotation at a rate of 17 deg/day on average. The total amplitude of the rotation is ~300 deg so far. The polarization fraction has been fluctuating between 0.5% and 8% during the rotation period, which is rather typical for this source (e.g. ATel #9179). The R-band light curve shows a flare with the peak value R=15m reached on August, 8 (c.f. ATels #7829, #2045). Our preliminary analysis of the publicly available Fermi LAT data for the blazar also reveals a flare in the gamma-ray band (E>100MeV) peaking on August, 8 at daily averaged photon flux level (2.1+/-0.3)x10^-6 ph cm^-2 s^-1 (c.f. ATels #3473, #3694).
Multifrequency observations of the blazar are encouraged.
The RoboPol program aims at understanding the AGN physics through optical linear polarization monitoring of a large sample of gamma-ray loud blazars as well as a comparison sample of gamma-ray quiet ones. It utilizes a novel-design 4-channel optical polarimeter mounted at the 1.3-m Skinakas telescope in Crete. It is a collaboration between the University of Crete (Greece), Max-Planck-Institut fur Radioastronomie (Germany), California Institute of Technology (USA), Nicolaus Copernicus University (Poland) and the Inter-University Centre for Astronomy and Astrophysics, (India).