Search Publications
Observations of interacting galaxies NGC 2341 and NGC 2342 in X-ray band
Tugay, A. V.; Shevchenko, S. Yu.; Ponomarenko, O. O.
The study of radiation of the interacting galaxies in different ranges enables to identify various processes occurring in them. The most active processes (such as star birth, material accretion onto the black holes, burster flashes, etc.) cause the appearance of X-rays. In our work, we studied the nature of the interacting pair of galaxies NGC 234…
Kinematic and dynamic properties of young stellar cluster IC 348
Nikoghosyan, E. H.; Azatyan, N. M.; Harutyunian, H. A. +1 more
In 30 - 40s of the last century Viktor Ambartsumian has published several studies on the kinematics and dynamics of stellar systems. The scientific issues of these papers not only remain relevant up to nowadays, but also are of key importance for the construction of the generalized theory of star formation. The launch of the Gaia spacecraft on Dec…
The Bright X-Ray Source in NGC 3413
Sonbas, E.; Dhuga, K. S.; Göğüş, E.
The emission-line dwarf galaxy NGC 3413 is known to host a bright X-ray source near its optical center. The 0.3-10 keV luminosity of this source is estimated to be approximately 1039 erg s-1, potentially qualifying it as an ultraluminous X-ray source (ULX). A recent X-ray Multi-Mirror Mission-Newton observation suggests that …
Understanding Magneto-convection on Solar Surface with Hinode Satellite Observation
Iida, Yusuke
The nature of X-ray spectral variability in SWIFT J2127.4+5654
Papadakis, I. E.; Kammoun, E. S.
We study the flux-flux plots (FFPs) of the Seyfert galaxy SWIFT J2127.4+5654 which was observed simultaneously by XMM-Newton and NuSTAR. The 0.7-2 keV FFPs show a non-linear behaviour, while they are well fitted by a straight line, in the ∼ 2-40 keV range. Without any additional modelling, this result strongly suggests that neither absorption nor …
Kinematics of the Milky Way from Velocities of Young Red Clump Giants Using the PMa and Gaia DR2 Data
Fedorov, P. N.; Velichko, A. B.
Subsample of 19,600 young red clump giants with distances up to 1200 pc was selected from 7.2 mln Gaia DR2 data with radial velocities using the MG vs. G - KS diagram. Ages of these stars do not exceed 2 bln years. For this stellar subsample kinematic parameters of the Ogorodnikov-Milne model as well as the Kxy-ter…
Identifying birth places of high-velocity stars
Hambaryan, V.
We searched for the high-velocity and isolated neutron stars that encountered in the past with a stellar cluster/association closer than 20 pc. We took about 830000 stars with the high-quality astrometry and radial velocities from the Gaia DR2 catalogue and empirically selected about 560 high-velocity stars. We used a full gravitational potential …
Radial Velocity Variations of ADS 3085 A and B
Sato, Bun'ei; Itoh, Yoichi; Katoh, Noriyuki
Some observations have indicated that the binary frequency of pre-main-sequence stars is higher than that of main-sequence stars. Several hot jupiters which are gas planets with the orbital period of days are discovered in the main-sequence stars (e.g., Mayor & Queloz 1995). Most of the main-sequence stars may be formed as the binary system. T…
Using the Subsurface Soil Sounding Radar for Investigating the Structure and Total Electron Content of the Martian Ionosphere
Smirnov, V. M.; Yushkova, O. V.; Marchuk, V. N.
The possibilities of using the Martian soil subsurface sounding radar for investigating the structure of the plasma shell surrounding the planet have been considered. Based on the numerical modeling results and actual soil sounding data, it has been shown that the soil sounding mode of the radio-locating MARSIS radar can be used to assess the stru…
9C spectral-index distributions and source-count estimates from 15 to 93 GHz - a re-assessment
Pooley, G. G.; Waldram, E. M.; Bolton, R. C. +1 more
In an earlier paper (2007), we used follow-up observations of a sample of sources from the 9C survey at 15.2 GHz to derive a set of spectral-index distributions up to a frequency of 90 GHz. These were based on simultaneous measurements made at 15.2 GHz with the Ryle telescope and at 22 and 43 GHz with the Karl G. Jansky Very Large Array (VLA). We …