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Title: Flux and Polarization Variability of OJ 287 during the Early 2016 Outburst

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 χ {sup 2}-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 δ {sub 0}=1.17, the magnetic field strength B≤3.8 G, and the size of the emitting region R{sub s}<2.28× 10{sup 14} 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 -bandmore » 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.« less

Authors:
; ; ;  [1];  [2]
  1. Indian Institute of Astrophysics, Block II, Koramangala, Bangalore-560034 (India)
  2. Aryabhatta Research Institute of Observational Sciences (ARIES), 263002, Nainital (India)
Publication Date:
OSTI Identifier:
22663912
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 835; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BL LACERTAE OBJECTS; BRIGHTNESS; CORRELATIONS; COSMIC GAMMA SOURCES; DOPPLER EFFECT; GALAXIES; GAMMA RADIATION; MAGNETIC FIELDS; PHOTOMETRY; POLARIMETRY; POLARIZATION; STATISTICS; WAVELENGTHS

Citation Formats

Rakshit, Suvendu, Stalin, C. S., Muneer, S., Paliya, Vaidehi S., and Neha, S., E-mail: suvenduat@gmail.com. Flux and Polarization Variability of OJ 287 during the Early 2016 Outburst. United States: N. p., 2017. Web. doi:10.3847/1538-4357/835/2/275.
Rakshit, Suvendu, Stalin, C. S., Muneer, S., Paliya, Vaidehi S., & Neha, S., E-mail: suvenduat@gmail.com. Flux and Polarization Variability of OJ 287 during the Early 2016 Outburst. United States. doi:10.3847/1538-4357/835/2/275.
Rakshit, Suvendu, Stalin, C. S., Muneer, S., Paliya, Vaidehi S., and Neha, S., E-mail: suvenduat@gmail.com. Wed . "Flux and Polarization Variability of OJ 287 during the Early 2016 Outburst". United States. doi:10.3847/1538-4357/835/2/275.
@article{osti_22663912,
title = {Flux and Polarization Variability of OJ 287 during the Early 2016 Outburst},
author = {Rakshit, Suvendu and Stalin, C. S. and Muneer, S. and Paliya, Vaidehi S. and Neha, S., E-mail: suvenduat@gmail.com},
abstractNote = {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 χ {sup 2}-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 δ {sub 0}=1.17, the magnetic field strength B≤3.8 G, and the size of the emitting region R{sub s}<2.28× 10{sup 14} 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.},
doi = {10.3847/1538-4357/835/2/275},
journal = {Astrophysical Journal},
number = 2,
volume = 835,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}