Search Publications
Study of the fast X-ray transient XTE J1901+014 based on INTEGRAL, RXTE, and ROSAT data
Lutovinov, A. A.; Karasev, D. I.; Grebenev, S. A.
The source XTE J1901+014 discovered by the RXTE observatory during an intense outburst of hard radiation and classified as a fast X-ray transient is studied. The source’s spectral characteristics in the quiescent state have been investigated for the first time both in the soft X-ray energy range (3 20 keV) based on ROSAT and RXTE data and in the h…
Ultraviolet spectrum of FU Ori and a ``Compromise'' model of the FUor
Errico, L.; Lamzin, S. A.; Kravtsova, A. S. +1 more
We have analyzed the Hubble Space Telescope spectrum of the young star FU Ori in the range 2300 3100 Å. The long-wavelength part of the spectrum is similar to the spectrum of a supergiant with T eff ≃ 5000 6000 K, but the range of wavelengths shorter than ≃2600 Å is dominated by radiation from a region with T eff ≃ 9000 K. We…
HUDF 1619—A candidate for polar-ring galaxies in the Hubble Ultra Deep Field
Dettmar, R. -J.; Reshetnikov, V. P.
A galaxy that is a good candidate for polar-ring galaxies has been detected in the Hubble Ultra Deep Field (HUDF). The galaxy HUDF 1619 (V ≈ 25 m , z ∼ 1) is the most distant object of this type known to date. A large-scale structure crosses the highly warped disk of the main galaxy seen almost edge-on at an angle of about 70°. The lumi…
High-mass X-ray binaries and the spiral structure of the host galaxy
Gilfanov, M. R.; Shtykovskiy, P. E.
We investigate the manifestation of the spiral structure in the distribution of high-mass X-ray binaries (HMXBs) over the host galaxy. We construct the simplest kinematic model. It shows that the HMXBs should be displaced relative to the spiral structure observed in such traditional star formation rate indicators as the Hα and far-infrared emissio…
Extrasolar low-orbit planets: Dissipation of their atmospheres and probable magnetic field
Ksanfomality, L. V.
Analysis of the data obtained during transits of low-orbit extrasolar planets across the stellar disk yields different estimates of their atmospheric loss rates. Experimental data point to the probable existence of several distinct subtypes of extrasolar giant planets, including "hot Jupiters" of low density (HD 209458b), with massive cores compos…
Cosmic GRB 060428C detected in the field of view of the IBIS and SPI telescopes onboard the INTEGRAL observatory and its early afterglow
Grebenev, S. A.; Chelovekov, I. V.
While analyzing the archival data of the INTEGRAL observatory, we detected and localized a cosmic gamma-ray burst recorded on April 28, 2006, by the IBIS/ISGRI and SPI telescopes in their fields of view. Since the burst was not revealed by the INTEGRAL burst alert system (IBAS), information about its coordinates was not distributed in time and no …
Development dynamics of intense solar proton flares
Zimovets, I. V.; Struminsky, A. B.
We consider the relationship of electromagnetic radiation in the three most intense flares of solar cycle 23, more specifically, those of October 28, 2003, January 20, 2005, and September 7, 2005, to the acceleration and release of protons into interplanetary space. The impulsive phase of these flares lasted ∼ 20 min and consisted of at least thre…
INTEGRAL observations of the gamma-ray burst on March 11, 2007
Sunyaev, R. A.; Sazonov, S. Yu.; Molkov, S. V.
On March 11, 2007, the INTEGRAL observation discovered and localized a gamma-ray burst in the sky from which an early infrared afterglow was then detected. We present our timing and spectral analyses of the data from the ISGRI detector of the IBIS telescope. The burst consists of one ∼40-s-long peak during which a fluence of ∼3 × 10-6 e…
Red giants in the blue compact galaxy IZw18
Tikhonov, N. A.
Archival Hubble Space Telescope (HST) data have been used for the photometry of stars in blue compact dwarf (BCD) galaxies of the IZw18 system. Applying the spatial selection of stars, we have detected red giants, stars older than 1 2 Gyr, in the galaxies. These red giants have allowed the distance to IZw18 to be reliably determined for the first …
Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system
Gontcharov, G. A.
The Pulkovo Compilation of Radial Velocities (PCRV) has been made to study the stellar kinematics in the local spiral arm. The PCRV contains weighted mean absolute radial velocities for 35 495 Hipparcos stars of various spectral types and luminosity classes over the entire celestial sphere mainly within 500 pc of the Sun. The median accuracy of th…