Search Publications
The first observation of AX J1749.1-2733 in a bright X-ray state—Another fast transient revealed by INTEGRAL
Sunyaev, R. A.; Grebenev, S. A.
An intense outburst of hard radiation (with a peak flux of ∼50 mCrab) was detected from the X-ray transient AX J1749.1-2733 by the IBIS/ISGRI gamma-ray telescope onboard the INTEGRAL observatory when the Galactic center field was monitored on September 8 10, 2003. Previously, this source had never been observed in a bright X-ray state. During the …
4U 0115+63 from RXTE and INTEGRAL data: Pulse profile and cyclotron line energy
Sunyaev, R. A.; Tsygankov, S. S.; Lutovinov, A. A. +1 more
We analyze the observations of the transient X-ray pulsar 4U 0115+63 with the RXTE and INTEGRAL observatories in a wide X-ray (3-100 keV) energy band during its intense outbursts in 1999 and 2004. The energy of the fundamental harmonic of the cyclotron resonance absorption line near the maximum of the X-ray flux from the source (luminosity range 5…
Detection of the first thermonuclear X-ray burst from AX J1754.2-2754
Grebenev, S. A.; Chelovekov, I. V.
When analyzing the archival data of the INTEGRAL observatory, we detected an intense X-ray burst recorded on April 16, 2005, by the JEM-X and IBIS/ISGRI telescopes from the weak and poorly studied source AX J1754.2-2754. Analysis of its time profiles and spectra allows this event to be attributed to type I X-ray bursts associated with thermonuclea…
High-mass X-ray binaries and recent star formation history of the Small Magellanic Cloud
Gilfanov, M. R.; Shtykovskiy, P. E.
We study the relation between high-mass X-ray binary (HMXB) population and recent star formation history (SFH) for the Small Magellanic Cloud (SMC). Using archival optical SMC observations, we have approximated the color-magnitude diagrams of the stellar population by model stellar populations and, in this way, reconstructed the spatially resolved…
Fine structure of decametric type II radio bursts
Konovalenko, A. A.; Chernov, G. P.; Stanislavsky, A. A. +3 more
We have performed a comparative analysis of the fine structure of two decametric type II bursts observed on July 17 and August 16, 2002, with the 1024-channel spectrograph of the UTR-2 radio telescope in the frequency range 18.5 29.5 MHz and with the IZMIRAN spectrograph in the frequency range 25 270 MHz. The August 16 burst was weak, ∼2 5 s.f.u.,…
Young nuclei in dwarf elliptical galaxies
Prugniel, Ph.; Afanasiev, V. L.; Chilingarian, I. V. +1 more
We report the discovery of young embedded structures in three diffuse elliptical galaxies (dE) in the Virgo cluster: IC 783, IC 3468, and IC 3509. We performed 3D spectroscopic observations of these galaxies with the MPFS spectrograph at the 6-m Special Astrophysical Observatory telescope and obtained spatially resolved distributions of kinematic …
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…