Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/7084
Title: Flux and polarization variability of OJ 287 during the early 2016 outburst
Authors: Rakshit, S
Stalin, C. S
Muneer, S
Neha, S
Paliya, Vaidehi S
Keywords: BL Lacertae objects: individual ( OJ 287 );Galaxies: photometry;Polarization
Issue Date: 1-Feb-2017
Publisher: IOP Publishing
Citation: The Astrophysical Journal, Vol. 835, No. 2, 275
Abstract: The gamma-ray blazar OJ 287 was in a high activity state during 2015 December–2016 February. Coinciding with this high brightness state, we observed this source for photometry on 40 nights in R-band and for polarimetry on nine epochs in UBV RI bands. During the period of our observations, the source brightness varied from 13.20 ± 0.04 mag to 14.98 ± 0.04 mag and the degree of polarization (P) fluctuated between 6.0% ± 0.3% and 28.3% ± 0.8% in R-band. Focusing on intranight optical variability (INOV), we find a duty cycle of about 71% using χ2-statistics, similar to that known for blazars. From INOV data, the shortest variability timescale is estimated to be 142 ± 38 minutes, yielding a lower limit of the observed Doppler factor δ0 = 1.17, the magnetic field strength B ≤ 3.8 G, and the size of the emitting region Rs < 2.28 × 1014 cm. On internight timescales, a significant anticorrelation between R-band flux and P is found. The observed P at U-band is generally larger than that observed at longer-wavelength bands, suggesting a wavelength-dependent polarization. Using V-band photometric and polarimetric data from Steward Observatory obtained during our monitoring period, we find a varied correlation between P and V-band brightness. While an anticorrelation is sometimes seen between P and V-band magnitude, no correlation is seen at other times, thereby suggesting the presence of more than one short-lived shock component in the jet of OJ 287.
Description: Restricted Access
URI: http://hdl.handle.net/2248/7084
ISSN: 0004-637X
???metadata.dc.rights???: © The American Astronomical Society
???metadata.dc.relation.uri???: https://doi.org/10.3847/1538-4357/835/2/275
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