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Scientific achievements, Metagalaxy sector

 2017: 


Inclinations and structure of central regions of active galaxies from observations in polarized light
From the analysis of changes of polarization plane in broad emission line profiles of hydrogen, black hole masses were estimated for the sample of 29 Sy1 galaxies using the method independent of the inclination angle of a galaxy to the line of sight. We have derived inclination angles of broad-line regions (BLR) of disks to the line of sight with the use of the literature data on BLRs and line widths measured with the 6-m BTA telescope as well as mass estimates from polarization. Inclination angles determined in such a way are in the range of 20-40o and correlate well (r~0.86) with inclination angles of galactic disks. Within a simple model of equatorial scatter of BLR emission in a gas and dust torus, it is shown that BLR disks in the galaxies of our sample are similar, and the brightness distribution for them can be described with the power-law dependence on the radius with a power exponent of -0.57.
Authors:
Afanasiev V.L. and Shapovalova A.I. (SAO RAS) in collaboration with Popovic L.C. (Belgrade Astronomical Observatory, Serbia).
Published:
1. Afanasiev V.L., Popovic L.C., Shapovalova A.I. Spectropolarimetry of Seyfert 1 galaxies with equatorial scattering: Black hole masses and Broad Line Region characteristics, 2018, MNRAS, http://adsabs.harvard.edu/doi/10.1093/mnras/sty2995
2. Afanasiev V.L., Popovic L.C., Polarization in lines - a new method for measuring black hole masses in active galaxies , 2015, ApJ L, V 800, L35


Discovery of a dwarf companion of a dwarf galaxy
A galaxy of extremely low luminosity was discovered in images obtained with the ACS camera of the Hubble Space Telescope nearby the dwarf galaxy LV J1157+5638. Such a remote faint galaxy has been discovered for the first time ever. In the galaxies of interest, individual stars are clearly observed including red giant branch stars. This galaxy pair is located at a distance of about 30 million light-years from Earth. According to our studies, the dwarf galaxies make a physical pair.
Authors:
Makarova L.N., Makarov D.I., Antipova A.V., Karachentsev I.D. (SAO RAS) in collaboration with Tully R.B. (Hawaii's Institute for Astronomy, USA)
Published:
Makarova L.N., Makarov D.I., Antipova A.V., Karachentsev I.D., Tully R.B., Serendipitous discovery of a faint dwarf galaxy near a Local Volume dwarf, 2017, MNRAS, 474, 3


Detection of overdensity excess of field galaxies near a redshift of z≈0.56 around the gamma-ray burst GRB 021004 position
Characteristic features of clusterization of field galaxies toward the gamma-ray burst GRB 021004 were detected: 1) distribution of photometric redshifts in the BTA field (of a size of ~ 4'x4') GRB 021004 with a peak at about z~0.56, determined from the multi-color BVRI photometry toward this gamma-ray burst + HST/ACS data; 2) the absorption doublet Mg II 2796/2803Å at a redshift of z≈0.56 found in the VLT/UVES spectrum of the gamma-ray burst afterglow; 3) clusterization of galaxies in the greater region (~ 3x3 square degrees) around the GRB 021004 with the effective peak at about z~0.56 found from the spectral and photometric z distributions using new catalogs. According to the data from six catalogs, the sizes of the whole inhomogeneity were estimated ~7±1 in the distribution of galaxy clusters with the peak at about z≈0.56.
Authors:
Zhelenkova, O.P., Verkhodanov, O.V., Sokolov, V.V. in collaboration with Sokolov, I.V. (Institute of Astronomy of the Russian Academy of Sciences), Castro-Tirado A.J. (IAA, Spain), Sokolov, I.A. (Saint Petersburg State University), Baryshev Yu.V. (Saint Petersburg State University).
Published:
1. Sokolov, Ilya V.; Castro-Tirado, A.J.; Verkhodanov, O.V.; Zhelenkova, O.P.; Baryshev, Yu.V., "Clustering of galaxies around the GRB 021004 sight-line at z ~ 0.5" in "Proceedings of the International Workshop on Quark Phase Transition in Compact Objects and Multimessenger Astronomy: Neutrino Signals, Supernovae and Gamma-Ray Bursts", Russia, Nizhnij Arkhyz (SAO RAS), Terskol (BNO INR RAS), October, 7 - 14, 2015, pp. 111, Publishing house "Sneg", Pyatigorsk, 2016. (http://adsabs.harvard.edu/abs/2016qptc.conf.111S)
2. Yu.V.Baryshev, I.V.Sokolov, A.S.Moskvitin et al., "Study of Faint Galaxies in the Field of GRB 021004", Astrophysical Bulletin, 65, 311 (2010), (http://arxiv.org/abs/1010.3910)
3. Sokolov Ilya V., Zhelenkova Olga P., Solovyev Ilya A., Castro-Tirado Alberto J., and Verkhodanov Oleg V., The Excess Density of Field Galaxies near z∼0.56" around the Gamma-Ray Burst GRB021004 Position, 2018, Astrophysical Bulletin, 73, 2


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