Search Publications
Estimation of the galactic spiral pattern speed from Cepheids
Bobylev, V. V.; Bajkova, A. T.
To study the peculiarities of the Galactic spiral density wave, we have analyzed the space velocities of Galactic Cepheids with propermotions from the Hipparcos catalog and line-of-sight velocities from various sources. First, based on the entire sample of 185 stars and taking R 0 = 8 kpc, we have found the components of the peculiar so…
Spatial distribution and kinematics of OB stars
Gontcharov, G. A.
The sample of 37 485 suspected OB stars selected by Gontcharov (2008) from the Tycho-2 catalogue has been cleaned of the stars that are not of spectral types OV-A0V. For this purpose, the apparent magnitude V T from Tycho-2, the absolute magnitude M_{V_T } calibrated as a function of the dereddened color index ( B T - V <…
Accurate localization and identification of six hard X-ray sources from Chandra and XMM-Newton data
Lutovinov, A. A.; Revnivtsev, M. G.; Karasev, D. I. +1 more
We present the results of Chandra and XMM-Newton observations for six hard X-ray sources (IGR J12134-6015, IGR J18293-1213, IGR J18219-1347, IGR J17350-2045, IGR J18048-1455, XTE J1901+014) from the INTEGRAL all-sky survey. Based on these observations, we have improved significantly the localization accuracy of the objects and, therefore, have man…
Optical identification of six hard X-ray sources from the INTEGRAL and SWIFT all-sky surveys
Bikmaev, I. F.; Lutovinov, A. A.; Revnivtsev, M. G. +1 more
We present results of optical identifications of six hard X-ray sources from the INTEGRAL and Swift all-sky surveys (IGR J03249+4041, SWIFT J1449.5+8602, SWIFT J1542.0-1410, IGR J17009+3559, IGR J18151-1052, IGR J18538-0102). Our optical observations were performed in 2009-2011 with the 6-m BTA telescope (Special Astrophysical Observatory, Nizhnii…
Dependence of kinematics on the age of stars in the solar neighborhood
Gontcharov, G. A.
The variations of kinematic parameters with age are considered for a sample of 15 402 thin-disk O-F stars with accurate α, δ, µ, and π > 3 mas from the Hipparcos catalogue and radial velocities from the PCRV catalogue. The ages have been calculated from the positions of the stars on the Hertzsprung-Russell diagram relative to the isochrones fro…
GRB 070912—A gamma-ray burst recorded from the direction to the galactic center
Frederiks, D. D.; Minaev, P. Yu.; Pozanenko, A. S. +3 more
The detection of GRB 070912 recorded in the field of view of the SPI, IBIS/ISGRI, and JEMX telescope on September 12, 2007, at 07h32m19s (UT) when analyzing the INTEGRAL archival data is reported. The burst is one of the well-localized events closest to the direction toward the Galactic center (less than [InlineMed…
Kinematics of stars in the northern and southern galactic hemispheres
Tsvetkov, A. S.; Vityazev, V. V.
We use vector spherical harmonics for a kinematic analysis of the proper motions of stars from the Hipparcos, Tycho-2, and UCAC3 catalogues in the northern and southern Galactic hemispheres. We have found that the statistically reliable values of the Ogorodnikov-Milne model parameters M {32/+} and M {32/-
Stellar subsystems of different ages in spiral and irregular galaxies
Tikhonov, N. A.; Galazutdinova, O. A.
Based on archival Hubble Space Telescope images, we have performed stellar photometry for eight edge-on spiral and irregular galaxies. We have identified stars of three ages in the derived Hertzsprung-Russell diagrams and constructed their number density distribution perpendicularly to the plane of the galactic disk. The sizes of the stellar subsy…
Expansion of the stellar subsystems of disk galaxies
Tikhonov, N. A.
Based on archival Hubble Space Telescope images, we have performed stellar photometry for eight edge-on spiral and irregular galaxies. We have identified stars with ages of 20, 50, 80, 160, and 500 Myr in the derived Hertzsprung-Russell diagrams and constructed their number density distributions perpendicularly to the plane of the galactic disk. W…
Luminosity function of high-mass X-ray binaries and anisotropy in the distribution of active galactic nuclei toward the Large Magellanic Cloud
Tsygankov, S. S.; Lutovinov, A. A.; Grebenev, S. A.
In 2003-2012, the INTEGRAL observatory has performed long-term observations of the Large Magellanic Cloud (LMC). At present, this is one of the deepest hard X-ray (20-60 keV) surveys of extragalactic fields in which more than 20 sources of different natures have been detected. We present the results of a statistical analysis of the population of h…