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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,
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
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