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Traces of recent interactions in active isolated galaxies
Extensive tidal envelopes surrounding a number of active (Seyfert)
galaxies, which were previously considered to be not interacting were
discovered on the BTA. It is shown that in a sample of active isolated
galaxies about 35% have undergone a merger with another galaxy during
the last 0.5-1 billion years. It is noted that statistical studies,
based on the digital sky surveys lead to an underestimation of the
proportion of small mergers among the galaxies with active nuclei.
(Contacts: A.V.Moiseev)
Posted: MNRAS, vol.408, p.400, 2010.
Study of star formation in dwarf galaxies
The history of star formation in dwarf galaxies outside the Local Group
(KDG61 and KDG64 in the M81 group of galaxies) was analyzed for the
first time. The BTA spectra and direct imaging form the Hubble Space
Telescope were used, yielding consistent results. Both galaxies are
dominated by old stellar population (12-14 million years) of low
metallicity ([Fe/H] ~ -1.5), 1.4 billion year old stars with a slight
enrichment by metals are as well present. No radial gradient in age and
metallicity of the stellar population was found.
In collaboration with the Observatory of Lyon, France
(Contacts: D.Makarov)
Study of radio spectra and variability of GPS-sources
The RATAN-600 studies have confidently identified 33 GPS (Gigahertz
Peaked Spectrum) sources. A steeper drop was detected in the electron
energy distribution for the GPS-galaxies, rather than for the GPS-quasars -
the difference of the exponent is of about 0.46. The "steepening" of
the galaxy spectra is possibly due to additional (with regards to
quasars) aging-linked energy losses for radiation, or the sample
galaxies may have been born later than quasars (at small z) and there
exists a cosmological difference in the energy spectra of electrons.
In collaboration with the Metsahovi Radio Observatory
(Contacts: Mingaliev M.G.)
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