• A. P. Marscher

      Articles written in Journal of Astrophysics and Astronomy

    • Multi-Frequency Observations of Gamma-Ray Blazar 1633+382

      S. G. Jorstad A. P. Marscher I. Agudo P. S. Smith V. M. Larionov A. Lähteenmäki

      More Details Abstract Fulltext PDF

      We perform monthly monitoring of the quasar 1633+382 (4C+38.41) within a sample of 𝛾-ray blazars with the VLBA at 43 GHz along with optical photometric and polarimetric observations. We construct the 𝛾-ray light curve of 1633+382 using data obtained by the Fermi LAT. We find that a high 𝛾-ray state of the quasar starting in 2009 September is simultaneous with an increase of the flux in the mm-wave VLBI core. We resolve a superluminal feature on the VLBA images that appears to be responsible for the mm-wave flux increase. We find a strong correlation between optical and 𝛾-ray light curves with a delay of 𝛾-ray variations of 5 ± 3 days, as well as a strong correlation between optical flux and degree of polarization during the high 𝛾-ray state. Comparison between the optical polarization position angle and that in the VLBI core supports the idea that in the quasar 1633+382 a high 𝛾-ray state is connected with processes originating near the mm-VLBI core.

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