Том 71, № 2 (2016)

We used the Revised Flat Galaxy Catalog (RFGC) to select 817 ultra-flat (UF) edge-on disk galaxies with blue and red apparent axial ratios of (a/b)_B > 10.0 and (a/b)_R > 8.5. The sample covering the whole sky, except the Milky Way zone, contains 490 UF galaxies with measured radial velocities. Our inspection of the neighboring galaxies around them revealed only 30 companions with radial velocity difference of | ΔV |< 500 kms⁻¹ inside the projected separation of R_p < 250 kpc. Wherein, the wider area around the UF galaxy within R_p < 750 kpc contains no other neighbors brighter than the UF galaxy itself in the same velocity span. The resulting sample galaxies mostly belong to the morphological types Sc, Scd, Sd. They have a moderate rotation velocity curve amplitude of about 120 km s⁻¹ and a moderate K-band luminosity of about 10¹⁰L_⊙. The median difference of radial velocities of their companions is 87 km s⁻¹, yielding the median orbital mass estimate of about 5 × 10¹¹M_⊙. Excluding six probable non-isolated pairs, we obtained a typical halo-mass-to-stellar-mass of UF galaxies of about 30, what is almost the same one as in the principal spiral galaxies, like M31 and M81 in the nearest groups. We also note that ultra-flat galaxies look two times less “dusty” than other spirals of the same luminosity.

Two quasars SDSS J010013.02+280225.8 and J030642.51+185315.8 with redshifts z = 6.30 and z = 5.363 were recently discovered. Their apparent magnitudes in the standard cosmological model give the luminosities of L_bol ∼ 4.3 × 10¹⁴L_⊙ and L_bol ∼ 3.4 × 10¹⁴L_⊙. In the framework of modern concepts it is accepted that the energy release of quasars is provided by the accretion onto black holes with masses of 1.24 ± 0.19 × 10¹⁰M_⊙ and 1.07 ± 0.27 × 10¹⁰M_⊙. As within the standard cosmological model the ages of these objects are about one billion years, this creates serious difficulties for the scenario of formation of such objects. Here we interpret the ultra-high luminosities of quasars as the effect of lensing of their radiation by the foreground globular clusters or dwarf galaxies.

We present a summary results of the study of radio sources showing significant variations of integral flux density using the data from the RATAN-600 surveys of 1980–1994 at a frequency of 7.6 cm. The majority of the detected variable sources have flat radio spectra, although there are also all other spectrum types found. Point and compact sources predominate, although all known morphological structures are found in the sample. Variability is detected both in quasars and galaxies. Using the catalog data, we found brightness variations in the optical and/or infrared ranges for a half of host objects of radio sources. We analyzed the properties of nonvariable and variable RCR sources. We compared the ratio of absolute magnitude to radio luminosity for sources with the active nucleus types determined from the optical data. It is found that this parameter is approximately the same for quasars with different radio luminosity. It isminimum for the strongest radio galaxies and grows up to the level characteristic of quasars with the decrease of radio luminosity. Considering that the ratio depends on obscuring properties of a dust torus, such behavior can be explained if we assume that the torus geometry and its optical depth depend on the source long. This parameter is slightly higher among variable sources than among nonvariable ones which counts in favor of the nucleus more open to an observer.

The axial rotation of a star plays an important role in its evolution, the physical conditions in its atmosphere and the appearance of its spectrum.We analyzed the CCD spectra of two stars for which their projected rotational velocity differs remarkably when derived from Ca II λ3933 Å and Mg II λ4481 Å lines. We estimated the projected rotational velocity of HD182255 to be 15.5 kms⁻¹, although in various spectra of this star the line widths correspond to values as high as 28.5 km s⁻¹. We found the HeI λ4471.498 Å line to be shifted to longer wavelengths by 0.046 Å, thus indicating a presence of the ³He I isotope in the atmosphere of this star with the ³He : ⁴He ratio from 0.2 to 0.6.We also found an absorption feature at the position of the forbidden line He I λ4470.02Å. We found the lines ofMg II and CII originating from higher excited levels to be missing in the spectra of HD 182255. For HD 214923 we determined the projected rotational velocity v sin i = 165km s⁻¹ from the profiles of the metallic lines and Ca II λ3933Å, whereas for helium lines v sin i ≈ 130km s⁻¹ is more appropriate. Radial velocity analysis results in three long periods of ≈ 105, 34, and 15 days, and a short period of ≈ 22 hours, close to the pulsational one mentioned earlier in the literature.

We present the results of 15184 astrometric observations of 322 visual binaries carried out in 2007–2014 at Pulkovo observatory. In 2007, the 26-inch refractor (F = 10413 mm, D = 65 cm) was equipped with the CCD camera FLI ProLine 09000 (FOV 12′ × 12′, 3056 × 3056 pixels, 0.238 arcsec pixel⁻¹). Telescope automation and weather monitoring system installation allowed us to increase the number of observations significantly. Visual binary and multiple systems with an angular distance in the interval 1.ʺ1–78.ʺ6 with 7.ʺ3 on average were included in the observing program. The results were studied in detail for systematic errors using calibration star pairs. There was no detected dependence of errors on temperature, pressure, and hour angle. The dependence of the 26-inch refractor’s scale on temperature was taken into account in calculations. The accuracy of measurement of a single CCD image is in the range of 0.ʺ0005 to 0.ʺ289, 0.ʺ021 on average along both coordinates. Mean errors in annual average values of angular distance and position angle are equal to 0.ʺ005 and 0.°04 respectively. The results are available here http://izmccd.puldb.ru/vds.htmand in the Strasbourg Astronomical Data Center (CDS). In the catalog, the separations and position angles per night of observation and annual average as well as errors for all the values and standard deviations of a single observation are presented. We present the results of comparison of 50 pairs of stars with known orbital solutions with ephemerides.

In this work, some solutions of magnetohydrodynamic (MHD) equations are searched in order to investigate some large scale physical quantities in the sunspot dominated latitudinal regions near the equatorial plane. Special separation of variables is used to obtain the radial and latitudinal changes in spherical coordinates. Present parametric analysis yields three important parameters which are the sphericity, density and radial components shape parameters in the latitudinal distributions of physical variables. In the region of interest there is a considerable change in physical quantities with respect to regions where sunspots do not appear.