most important scientific achievements for 2011–2015
Studying distributions of stars of different
ages in irregular and spiral galaxies we found for each galaxy a clear
correlation between the age of stars and the spatial size of the
subsystems of stars of this age. We believe that the dependency found
by us can
be explained by the hypothesis of galaxy expansion over time.
N., Galazutdinova O., AA Transac., V. 27, Iss.2, 227, 2012.
N., Galazutdinova O.,
Astronomy Letters, V.
38, Iss.3, p. 147, 2012.
Fig. 1. HST image of the PGC9962 galaxy (on top).
Hertzsprung-Russell diagram for this galaxy is shown with isochrones of different ages (in the bottom left corner)
and number density distribution diagrams for stars of different ages perpendicular to
disk plane (in the bottom right corner). The numbers on the diagrams denote the age of stars in millions of years.
NGC 1313 galaxy,
being, perhaps, the most
mysterious galaxy of the sky, has been studied based on the Hubble
Telescope images. In normal images, it looks like a normal spiral
but deep images show that the galaxy is highly distorted by
interaction. However, the images do not show any neighboring galaxy,
which would create the deformation of a stellar structure. We made a
photometry of eight NGC 1313 fields
of its dwarf companion AM 0319-662 and studied the visible distribution
of different ages and of metallicity in the galaxy. It has been found
spatial distribution of low metallicity stars is substantially
the distribution of high metallicity stars. This distinction has
us to identify the fragments of a dwarf galaxy destroyed by now, being
merged with NGC 1313. This disappeared galaxy was the cause of the
gravitational deformation of NGC 1313.
N., Galazutdinova O., Astronomy
Letters, submitted in 2015.
NGC 1313 (image made with 8 meter
3) We have developed the new
method for determining the size of groups and clusters of galaxies from cumulative distribution
of number of galaxies in
dependence on squared clustercentric distance. For 29 systems of galaxies we have determined
dynamical masses within the effective radius Re which are about 1.65 times less then masses enclosed within R200
radius. A comparison of the
inferred dynamical masses and the
hydrostatic masses determined from the radiation of hot gas in galaxy
groups and clusters (based on
published data) led us to conclude that the inferred masses for the
main sample of 21 groups and clusters, which does not include merging
clusters with irregular structure, the dynamical masses exceed the
X-ray masses an average by
12%, with an rms scatter of
A.I., Kopylova F.G., Ast. Bull., 70, 243,
Fig. 3. A comparison of
the X-ray masses (MX,200) obtained by gas radiation in
X-ray band with the dynamical masses (M200) measured from the radial velocities of galaxies. The objects of the main sample
are shown by filled circles.