Search Publications
Timing characteristics of the hard X-ray emission from bright X-ray pulsars based on INTEGRAL data
Tsygankov, S. S.; Lutovinov, A. A.
We review the results of a timing analysis of the observations for ten bright X-ray pulsars (with fluxes >100 mCrab in the 20-100 keV energy band) that fell within the INTEGRAL field of view from 2003 to 2007. The dependence of the pulse profile on the energy and intrinsic source luminosity has been investigated; particular attention has been p…
Analysis of the three-dimensional stellar velocity field using vector spherical functions
Tsvetkov, A. S.; Vityazev, V. V.
We apply vector spherical functions to problems of stellar kinematics. Using these functions allows all of the systematic components in the stellar velocity field to be revealed without being attached to a specific physical model. Comparison of the theoretical decomposition coefficients of the equations for a particular kinematical model with obse…
Stellar population of the irregular galaxy IC 10
Tikhonov, N. A.; Galazutdinova, O. A.
Based on our observations with the 6-m BTA telescope at the Special Astrophysical Observatory, the Russian Academy of Sciences, and archival Hubble Space Telescope images, we have performed stellar photometry for several regions of the irregular galaxy IC 10, a member of the Local Group. Distance moduli with a median value of m - M = 24.47, D = 78…
Stellar content of the interacting galaxies of the M51 system
Tikhonov, N. A.; Galazutdinova, O. A.; Tikhonov, E. N.
Based on archival Hubble Space Telescope ACS/WFC images, we have performed stellar photometry for more than 0.6 million stars in the interacting galaxies NGC 5194 and NGC 5195 of the M51 system. Stars of various ages have been identified on the constructed Hertzsprung-Russell diagram: blue and red supergiants, AGB stars, and red giants. The distan…
Kinematics of Tycho-2 red giant clump stars
Bobylev, V. V.; Bajkova, A. T.; Gontcharov, G. A. +1 more
Based on the Ogorodnikov-Milne model, we analyze the proper motions of 95,633 red giant clump (RGC) stars from the Tycho-2 Catalogue. The following Oort constants have been found: A = 15.9 ± 0.2 km s-1 kpc-1 and B = -12.0±0.2 km s-1 kpc-1. Using 3632 RGC stars with known proper motions, radial velocities, and photometric distances, we show that, a…
Using the reduced proper motions of Tycho-2 stars with B-V from 0.75 to 1.25: Monte Carlo simulations
Gontcharov, G. A.
The stellar composition of the Tycho-2 Catalogue in the range B-V = 0{·/ m }75-1{·/ m }25 has been reproduced through Monte Carlo simulations. For young and old stars of the red giant clump (RGC), the red giant branch, subgiants, red dwarfs, and thick-disk giants, we have specified the distributions in c…
Timing and spectral properties of the X-ray emission from the blazar 1ES 1426+428
Fidelis, V. V.; Yakubovskyi, D. A.; Voytkova, Yu. V.
Most of the extragalactic sources from which very-high-energy (VHE, E > 1011 eV) gamma-ray fluxes have been detected belong to the category of high-energy peaked BL Lacertae objects (HBLs)—the sources in which the synchrotron radiation peaks in the UV or X-ray band. They often have higher X-ray luminosities than the VHE gamma-ray ene…
Star formation history in the central region of the barred galaxy NGC 4245
Afanasiev, V. L.; Chilingarian, I. V.; Sil'Chenko, O. K.
We have investigated the gas and stellar kinematics and the stellar population properties at the center of the early-type galaxy NGC 4245 with a large-scale bar by the method of two-dimensional spectroscopy. The galaxy has been found to possess a pronounced chemically decoupled compact stellar nucleus, which is at least a factor of 2.5 richer in m…