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Discovery of new properties of the gravitationally lensed quasar Q0957+561
Gravitational lenses, responsible for the formation of multiple images of
distant objects (usually galaxies and quasars), are often used in modern
astrophysics to detect the large-scale distribution of matter in the
Universe. However, the study of the lensed images themselves makes it
possible to examine in more detail the structure of the central parsec
of the spatially unresolved active nuclei using direct optical methods.
During the observations of the lensed quasar Q0957+561 at the BTA of SAO RAS,
it was first discovered that the polarization vector is oriented in different
ways differently in two images of the source, and the polarization angle
changes with wavelength. Previously, similar properties were not observed
in gravitational objects. The effect can be described qualitatively by a
lensing model of the accretion disk as an extensive source with the
continuous polarization.
Authors:
V.L. Afanasiev,
E.S. Shablovinskaya (SAO RAS) in cooperation with L.C. Popovic,
Dj. Savic (Astronomical Observatory in Belgrade, Serbia)
Published:
1. Popovic L.C., Afanasiev V.L., Shablovinskaya E.S., Ardilanov V.I.,
Savic D. Spectroscopy and polarimetry of the gravitationally lensed quasar
Q0957+561, 2021, A&A, 647, A98. doi.org/10.1051/0004-6361/202039914
Search for "hibernating" active galactic nuclei by their ionization signs
in the intergalactic medium
The study of the ionization state of gaseous clouds outside the galactic
disks makes it possible to study the change in the intensity of ionizing
radiation associated with the activity of the central supermassive black
hole. For the first time, a search for such clouds has been performed in
a complete luminosity-limited sample of nearby galaxies with active nuclei.
Among 111 objects, the systems of ionized gas far from the nucleus
(25-75 kpc) were found in 3 cases. It was found that the activity in
NGC 5514 has more than 3 times decreased over the past 250 thousand years.
Also, in 4 galaxies, giant (up to 10 kpc) ionization cones were found
inside galactic disks. It is shown that in the overwhelming majority of
objects, ionized clouds belong to tidal structures associated with the
interaction of galaxies. The study of the state of gas ionization was
carried out with the telescopes: BTA SAO RAS, 2.6-m KGO SAI MSU, and
1.6-m ISTP SB RAS using the instruments created at SAO RAS (SCORPIO-1/2,
MaNGaL, ADAM).
Authors:
Moiseev A.V., Kozlova D.V., Ikhsanova A.I., Oparin D.V., Uklein R.I.
(SAO RAS) in cooperation with W.C. Keel (University of Alabama, USA),
Eselevich M.V. (ISTP SB RAS)
Published:
1. Keel W.C., Moiseev A., Kozlova D.V., Ikhsanova A.I., Oparin D.V.,
Uklein R.I., Smirnova A.A., Eselevich M.V., The TELPERION Survey for
Distant [O III] Clouds around Luminous and Hibernating AGN, Monthly
Notices of the Royal Astronomical Society, 510, 3, 2022, 4608–4625,
DOI: 10.1093/mnras/stab3656
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