Blazar Variability in Flux, Color, and Polarization Observed with the "Kanata" Optical-Near-Infrared Telescope
Abstract
We have performed photo-polarimetric observations of blazars using the Kanata 1.5-m telescope operated by Hiroshima University. We can obtain simultaneous optical and near-infrared (NIR) images using the instrument, TRISPEC, attached to Kanata. The main aim of our observation was follow-up observations of gamma-ray flares of blazars detected with Fermi. Besides multi-wavelength studies with Fermi, our optical-NIR monitoring data of 42 blazars give us a chance to study the blazar variability in flux, color, and polarization with a time-scale of days-months. Here, we summarize our findings through the observation. We confirmed a strong correlation between the flux and color: an object becomes bluer when it is brighter. This feature was observed about 90% of objects. On the other hand, the correlation between the flux and polarization is much weaker than the flux-color correlation. This is probably because there are multiple variation sources with different time-scales . A correlation between the flux and polarization could be disturbed because of the presence of another polarization component. We also comment possible collaborations between our optical-NIR observations of LBLs/FSRQs and X-ray observations of HBLs with MAXI.
- Publication:
-
The First Year of MAXI: Monitoring Variable X-ray Sources
- Pub Date:
- December 2010
- Bibcode:
- 2010fym..confP..45U