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Table · dataset · 2017

Polarization and photometry for blazar W Comae

Listed in IVOA Registry (Virtual Observatory)

An R-band photopolarimetric variability analysis of the TeV bright blazar W Comae between 2008 February 28 and 2013 May 17 is presented.

Description

The source showed a gradual tendency to decrease its mean flux level with a total change of 3 mJy. A maximum and minimum brightness states in the R band of 14.25+/-0.04 and 16.52+/-0.1 mag, respectively, were observed, corresponding to a maximum variation of {Delta}F=5.40 mJy.

We estimated a minimum variability timescale of {Delta}t=3.3 days. A maximum polarization degree P=33.8%+/-1.6%, with a maximum variation of {Delta}P=33.2%, was found. One of our main results is the detection of a large rotation of the polarization angle from 78{deg} to 315{deg} ({Delta}{theta}~237{deg}) that coincides in time with the {gamma}-ray flare observed in 2008 June.

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This result indicates that both optical and {gamma}-ray emission regions could be co-spatial. During this flare, a correlation between the R-band flux and polarization degree was found with a correlation coefficient of r_F-p _=0.93+/-0.11. From the Stokes parameters, we infer the existence of two optically thin synchrotron components that contribute to the polarized flux.

One of them is stable with a constant polarization degree of 11%. Assuming a shock-in jet model during the 2008 flare, we estimated a maximum Doppler factor {delta}_D_~27 and a minimum of {delta}_D_~16; a minimum viewing angle of the jet ~2.0{deg}; and a magnetic field B~0.12 G.

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Catalogue records · 2

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Stated by source
Optical
Provenance · 1 source records, 8 field assertions
SourceKeyLast seenRaw
IVOA Registry (Virtual Observatory)ivo://cds.vizier/j/apj/794/5414 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[field].local:field:astronomymapping · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].ivoa_waveband:opticalsource · IVOA Registryconnector:ivoa_registry@1.0.0
descriptionsource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_description
license_textsource · IVOA Registryconnector:ivoa_registry@1.0.0
publication_datesource · IVOA Registryconnector:ivoa_registry@1.0.0
titlesource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_title
updated_datesource · IVOA Registryconnector:ivoa_registry@1.0.0