Based on the measurements of the Stokes parameters in the continuum and in the broad 0.6563 nm hydrogen emission line obtained with the 6-m telescope for the Seyfert galaxy Mkn 6, secular variability of the hydrogen line profile polarization was discovered; a time lag of less than 2 days between the continuum flux and the polarized continuum emission was determined which corresponds to the size of the region where the polarization of the continuum occurs, less than 0.001 pc. The hydrogen line emission time lag is equal to approximately 20 days.
    An analysis of the data in the Stokes parameter plane shows that the polarization in the continuum is caused by the emission of the accretion disk and the relativistic jet, and by the scattering on the gas-and-dust torus in the case of the broad hydrogen lines. It was shown for the first time that the analysis of the polarization angle dependence on the velocity across the hydrogen line profiles due to the gas emission in the broad-line formation region near the massive AGN allows to determine directly from observations the type of motion in the broad-line formation region, which in the case of Mkn 6 turned out to be Keplerian at distances less than 0.02 pc from the nucleus. The lower mass limit determined for the supermassive black hole in the center of the Mkn 6 galaxy is equal to 150 million solar masses.
Published:
V.L.Afanasiev, L.C.Popovic, A.I.Shapovalova, N.V.Borisov, D.Ilic; Variability in Spectropolarimetric properties of Sy 1.5 galaxy Mrk6; eprint arXiv:1310.1179
In press:
V.L.Afanasiev, L.C.Popovic, A.I.Shapovalova, N.V.Borisov, D.Ilic; Variability in Spectropolarimetric properties of Sy 1.5 galaxy Mrk6; Mon.Not.R.Astron.Soc.