Search Publications
HD/H2 molecular clouds in the early Universe: The problem of primordial deuterium
Balashev, S. A.; Ivanchik, A. V.; Varshalovich, D. A.
We have detected new HD absorption systems at high redshifts, z abs = 2.626 and z abs = 1.777, identified in the spectra of the quasars J0812+3208 and Q1331+170, respectively. Each of these systems consists of two subsystems. The HD column densities have been determined: log N {HD/A} = 15.70 ± 0.07 for z…
Extended emission from short gamma-ray bursts detected with SPI-ACS/INTEGRAL
Minaev, P. Yu.; Pozanenko, A. S.; Loznikov, V. M.
The short duration ( T 90 < 2 s) gamma-ray bursts (GRBs) detected in the SPI-ACS experiment onboard the INTEGRAL observatory are investigated. Averaged light curves have been constructed for various groups of events, including short GRBs and unidentified short events. Extended emission has been found in the averaged light curves of b…
Searching for stars closely encountering with the solar system
Bobylev, V. V.
Based on a new version of the Hipparcos catalog and currently available radial velocity data, we have searched for stars that either have encountered or will encounter the solar neighborhood within less than 3 pc in the time interval from -2 Myr to +2 Myr. Nine new candidates within 30 pc of the Sun have been found. To construct the stellar orbits…
Analysis of peculiarities of the stellar velocity field in the solar neighborhood
Bobylev, V. V.; Bajkova, A. T.; Mylläri, A. A.
Based on a new version of the Hipparcos catalogue and an updated Geneva-Copenhagen survey of F and G dwarfs, we analyze the space velocity field of ≈17 000 single stars in the solar neighborhood. The main known clumps, streams, and branches (Pleiades, Hyades, Sirius, Coma Berenices, Hercules, Wolf 630- α Ceti, and Arcturus) have been identified us…
Parameters of the local warp of the stellar-gaseous galactic disk from the kinematics of Tycho-2 nearby red giant clump stars
Bobylev, V. V.
We analyze the three-dimensional kinematics of about 82 000 Tycho-2 stars belonging to the red giant clump (RGC). First, based on all of the currently available data, we have determined new, most probable components of the residual rotation vector of the optical realization of the ICRS/HIPPARCOS system relative to an inertial frame of reference, (…
Distance to the galaxy IC 342
Tikhonov, N. A.; Galazutdinova, O. A.
Based on archival Hubble Space Telescope images, we have performed stellar photometry for a region of the spiral galaxy IC 342 located in the Milky Way zone. On the constructed Hertzsprung-Russell diagram, we have identified the red giant branch and determined the distance modulus for the galaxy by the TRGB (tip of the red giant branch) method, ( …
Stars outside the Hipparcos list closely encountering the Solar system
Bobylev, V. V.
Based on currently available kinematic data, we have searched for stars outside the Hipparcos list that either closely encountered in the past or will encounter in the future the Solar system within several parsecs. For the first time, we have identified two single stars, GJ 3379 (G 099-049) and GJ 3323 (LHS 1723), as candidate for a close encount…
Investigation of the transient X-ray burster IGR J17380-3749 discovered by the INTEGRAL observatory
Grebenev, S. A.; Chelovekov, I. V.
Details of the discovery (in February 2004) and results of subsequent (in 2004-2009) INTEGRAL observations of the transient X-ray burster IGR J17380-3749 (IGR J17379-3747) are presented. Over the period of its observations, the INTEGRAL observatory recorded two hard X-ray flares and one type I X-ray burst from the source, which allowed the nature …
Astrometric study of the relative motion of three stars with possible invisible companions based on homogeneous series obtained at Pulkovo with a 26-inch refractor
Kiyaeva, O. V.; Izmailov, I. S.; Gorynya, N. A.
We investigate the relative motion of three stars, ADS 7446, 9346, and 9701, based on long-term observations with the Pulkovo 26-inch refractor. The relative motion of all three stars shows a perturbation that could be produced by the gravitational influence of an invisible companion. For ADS 7446, we have determined the orbit of the photocenter w…
IGR J16547-1916/1RXS J165443.5-191620—a new intermediate polar from the INTEGRAL galactic survey
Lutovinov, A. A.; Revnivtsev, M. G.; Burenin, R. A. +2 more
We present the results of our optical identification of the X-ray source IGR J16547-1916 detected by the INTEGRAL observatory during a deep all-sky survey. Analysis of the spectroscopic data from the SWIFT and INTEGRAL observatories in the X-ray energy band and from the BTA (Special Astrophysical Observatory) telescope in the optical band has show…