120692336
The optical system of the TUS space experiment
The TUS space experiment has been proposed to address some of the most important astrophysical and particle physics problems. It is aimed to study the energy spectrum, composition and angular distribution of Ultra High Energy Cosmic Rays (UHECR) at E ≈ 10 20 eV in the region of the GZK cutoff. The TUS mission is now planned for operation at the Small Space Apparatus (SSA) as an additional payload of the Foton-4 Russian-ESA satellite. The TUS optical system is an important part of the detector which will measure the fluorescence light radiated by EAS of the UHECR. It consists of a 7-segment Fresnel mirror-concentrator of 2 sq. m. The photo receiver at the mirror focal surface comprises 256 PMT pixels. In this paper the TUS optical system is described. Production of its technological prototype is in progress.
121298042
Separation of the electron component by the shower shape in an ionization calorimeter for the NUCLEON experiment
An ionization calorimeter introduced in the composition of the NUCLEON research equipment is described. The possibility of employing it to study the spectrum of the electromagnetic charged component of cosmic rays in the energy range of 100–2000 GeV is discussed on the basis of data from a simulation.
54933433
Pioneering space based detector for study of cosmic rays beyond GZK Limit
Space-based detectors for study of extreme energy cosmic rays (EECR) are being prepared as promising new direction of EECR study. Pioneering space device - tracking ultraviolet set up (TUS) is at the last stage of its construction and testing. TUS detector description is presented.
119302819
IGR J16547-1916/1RXS J165443.5-191620—a new intermediate polar from the INTEGRAL galactic survey
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 shown that the source is most likely an intermediate polar—an accreting white dwarf with the mass ofMWD μ 0.85M⊙ binary system. Subsequent studies of the object’s rapid variability with the RTT-150 telescope have confirmed this conclusion by revealing periodic pulsations of its optical emission with a period of ≈550 s.
56028541
Internal rotation of red giants by asteroseismology
We present an asteroseismic approach to study the dynamics of the stellar interior in red giant stars by asteroseismic inversion of the splittings induced by the stellar rotation on the oscillation frequencies. We show preliminary results obtained for the red giant KIC4448777 observed by the space mission Kepler.
118487818
Masses and accretion rates of supermassive black holes in active galactic nuclei from the INTEGRAL survey
The masses of 68 supermassive black holes (SMBHs) in nearby (z < 0.15) active galactic nuclei (AGNs) detected by the INTEGRAL observatory in the hard X-ray energy band (17–60 keV) outside the Galactic plane (|b| 5°) have been estimated. Well-known relations between the SMBHmass and (1) the infrared luminosity of the stellar bulge (from 2MASS data) and (2) the characteristics of broad emission lines (from RTT-150 data) have been used. A comparison with the more accurate SMBH mass estimates obtained by the reverberation-mapping technique and from direct dynamical measurements is also made for several objects. The SMBH masses derived from the correlation with the bulge luminosity turn out to be systematically higher than the estimates made by other methods. The ratio of the bolometric luminosity to the critical Eddington luminosity has been found for all AGNs. It ranges from 1 to 100% for the overwhelming majority of objects.
119196445
New cataclysmic variable 1RXS J073346.0+261933 in Gemini
In the course of our search for the optical identifications of ROSAT X-ray sources, we have found a highly variable object with a very unusual behavior on long time scales, rare color indices, and a high X-ray-to-optical flux ratio. We present the archival light curve from the Catalina Sky Survey, optical spectroscopy from RTT150, and time-resolved photometry from the Astrotel-Caucasus telescope. The object appears to be a magnetic cataclysmic variable (a polar) with an orbital period P = 3.20 h.
118342844
The orbits of subdwarf B + main-sequence binaries I: The sdB+G0 system PG 1104+243
Context. The predicted orbital period histogram of a subdwarf B (sdB) population is bimodal with a peak at short ( 250 days) periods. Observationally, however, there are many short-period sdB systems known, but only very few long-period sdB binaries are identified. As these predictions are based on poorly understood binary interaction processes, it is of prime importance to confront the predictions to well constrained observational data. We therefore initiated a monitoring program to find and characterize long-period sdB stars. Aims. In this contribution we aim to determine the absolute dimensions of the long-period binary system PG 1104+243 consisting of an sdB and a main-sequence (MS) component, and determine its evolution history. Methods. High-resolution spectroscopy time-series were obtained with HERMES at the Mercator telescope at La Palma, and analyzed to determine the radial velocities of both the sdB and MS components. Photometry from the literature was used to construct the spectral energy distribution (SED) of the binary. Atmosphere models were used to fit this SED and determine the surface gravity and temperature of both components. The gravitational redshift provided an independent confirmation of the surface gravity of the sdB component. Results. An orbital period of 753 ± 3 d and a mass ratio of q = 0.637 ± 0.015 were found for PG 1104+243 from the radial velocity curves. The sdB component has an effective temperature of Teff = 33 500 ± 1200 K and a surface gravity of log g = 5.84 ± 0.08 dex, while the cool companion is found to be a G-type star with Teff = 5930 ± 160 K and log g = 4.29 ± 0.05 dex. When a canonical mass