Luka Popović (Astronomical Observatory, Belgrade, Serbia), in collaboration with: V. L. Afanasiev, A. Moiseev, A. Smirnova, S. Simić, Dj. Savić, E. G. Mediavilla, C. Fian (SAO and IAC)
Spectroscopy and polarimetry of the gravitationally lensed quasar
Аннотация:
Gravitationally lensed quasars are very important for cosmological investigations, but also for investigation of the quasar structure. Especially in the case of a microlensing event, the variability in the image flux and spectra can indicate the structure of lensed source (quasar). Additionally, polarimetry of lensed quasars can give very useful information about the distribution of the dust sublimation region in these objects. Here we present our investigation of the inner structure of the lensed quasar SDSS J1004+4112 based on spectroscopic and polarimetric observations with 6m telescope SAO and theoretical model prediction. Quasar SDSS J1004+4112 is a four-image system (images A, B, C and D) with source redshift z = 1.734 and lens redshift z = 0.58. We explore spectral characteristics of these four components obtained at three different epochs (2007, 2008 and 2018) and polarization observed at seven epochs (2014–2017). We found that equatorial scattering in the inner part of the torus can explain the observed polarization, while amplification in the blue wing of CIV line observed only in the A component is probably caused by microlensing of an outflowing region.
(This talk is based on the paper which will appear in A&A, see https://arxiv.org/abs/1912.08886)