Astrophysical Bulletin

The spectral properties of inhomogeneities of the cosmic microwave background are considered. The inhomogeneity spectra are studied in the frequency range from 30 to 217 GHz according to multi-frequency maps of the Planck space mission with smoothing at different angular sizes. According to the thermodynamic temperature versus frequency relation, it is shown that the map at 70 GHz has a signal distribution that differs from the data at other frequencies depending on the smoothing window. At 70 GHz, there is a peak in the spectrum, most strongly manifested on maps without smoothing. In the inhomogeneity spectra represented by the frequency dependence of the flux density for data at high multipoles (ℓ > 200, θ < 30'), the signal behavior different from the low multipoles (ℓ < 200) was found, which demonstrates a monotonically growing spectrum with an increase in frequency from 30 to 217 GHz.

We study the nearest outskirts (R < 3R_200c) of 40 groups and clusters of galaxies of the local Universe (0.02 < z < 0.045 and 300 km s^-1 < σ < 950 km s^-1). Using the SDSS DR10 catalog data, we determined the stellar mass of galaxy clusters corresponding to K_s-luminosity (which we determined earlier based on the 2MASX catalog data) (M*/M_⊙) ∝ (L_K/L⊙)^1.010±0.004 (MK < - 21^m.5, R < R_200c). We also found the dependence of the galaxy cluster stellar mass on halo mass: (M*/M_⊙) ∝ (M_200c/M_⊙)^0.77±0.01. Our results show that the fraction of galaxies with quenched star formation (M_K < -21^m) is maximal in the central regions of the galaxy clusters and equals, on the average, 0.81 ± 0.02; it decreases to 0.44 ± 0.02 outside of the projected radius R_sp (2 < R/R_200c < 3), which we found from the observed profile, but still remains higher than that in the field by 27%. The fraction of early-type “red sequence” galaxies decreases from 0.54 ± 0.02 in the center to 0.24 ± 0.01 beyond R_sp, reaching its field value.

The improvement of the calibration relation for determining the size of the broad-line region from the observed optical luminosity of active galactic nuclei (AGN) is a necessary task to study fundamental parameters of distant AGNs such as mass of the central supermassive black hole. The most popular method of the BLRsize estimation is the reverberation mapping based onmeasuring the time delay between the continuum flux and the flux in the emission lines. In our work, we apply the method of photometric reverberation mapping in medium-band filters, adapted for observations at the Zeiss-1000 telescope of the SAO RAS, for the study of AGN with broad lines in the range of redshifts 0.1 < z < 0.8. This paper describes the technique of observations and data processing, provides a sample of objects and demonstrates the stability of the used method. As a preliminary result for 2MASXJ08535955+7700543 at z = 0.1 we have obtained time delay estimates of τ(ICCF) = 32.2^±10.6 days and τ(JAVELIN) = 39.5_−15.8^+23.0 days that are consistent with each other and also within the accuracy of the existing calibration relations.

A comprehensive statistical analysis of the relationship between the chemical and spatially kinematic parameters of the globular clusters of the Galaxy has been performed. The data of the author’s compilation catalog contain astrophysical parameters for 157 clusters and the relative abundances of α-elements for 69 clusters. For 121 clusters, the data are supplemented by spatially kinematic parameters taken from the literature. The phenomenon of reddening of horizontal branches of low-metal accreted globular clusters is discussed. We consider the contradiction between the criteria for clusters to belong to the subsystems of the thick disk and the halo in terms of chemical and kinematic properties. It consists in the fact that, regardless of belonging to the galactic subsystems by kinematics, almost all metallic ([Fe/H] >–1.0) clusters are located close to the center and plane of the Galaxy, while among the less metallic of both subsystems there are many distant ones. Differences in the abundances of α-elements in the stellar objects of the Galaxy and the surrounding low-mass dwarf satellite galaxies confirm the well-known conclusion that all globular clusters and field stars of the accreted halo are remnants of galaxies of higher mass than the current environment of the Galaxy. A possible exception is a distant low-metal cluster with low relative abundance of α-elements Rup 106.

We study relations of the parameter R_var (amplitude of the brightness variability, stellar activity indicator) with respect to the effective temperature and the period of rotation of stars belonging to the A–M spectral types. A common dataset gives an idea of variations in this parameter for stars with convection. It was confirmed that the limit of applicability for the gyrochronological relation PtM does not correspond to the limiting value (B - V )₀ 0.47, and the relationship between a rotation period and color is likewise visible up to groups of stars with (B - V )₀ = 0.2. It is shown that the value of the parameter R_var for stars with effective temperatures of 6500–7500 K are about an order of magnitude lower than that for stars, which indicates a nonmonotonic change of the parameter and, therefore, does not allow us to conclude that there is a single dependence of this parameter in the entire temperature range. In the diagram R_var–P (the rotation period), A-type stars fall in the sequence of fast-rotating active objects, whereas stars with similar temperatures and belonging to the F spectral type (including objects from the cluster NGC 6866) lie in a different sequence corresponding to fast-rotating objects with a small amplitude in the brightness variability. The existence of a unified relationship between the properties of rotational activity in stars of spectral types A, F, and later, as well as possible physical processes leading to the implementation of a standard gyrochronological ratio and activity in A stars are discussed.

We present an analysis of the spectra of the star V837 Tau, which belongs to a class of chromosphere-active RSCVn type stars. The observational material was obtained with the 1.5-m Russian-Turkish telescope RTT-150 and the 2.6-m Shajn telescope of the Crimean astrophysical observatory. To reveal signs of the photosphere spottedness of the primary and to isolate the faint secondary, we performed the deconvolution of the “averaged” spectral profile of the system. By describing the radial velocity curves, we refined the orbital elements of the binary system, and by modeling spectrawe determined the fundamental parameters of the components, as well as the chemical composition of the atmosphere of the bright component. Using the Doppler mapping method we reconstructed the distribution of spots on the surface of the bright star. We show that the spots are concentrated in a belt at medium (about 40) latitudes. The hydrogen line profiles have a variable emission feature in the bright component, and the Hα line exhibits traces of chromospheric activity in the secondary.

We present the results of long-term spectral monitoring of yellow hypergiants (YHGs) of northern hemisphere with a R ≥ 60 000 resolution. The spectra of these F–G stars of extreme luminosity, compactly located at the top of the Hertzsprung–Russell diagram revealed a variety of spectral features: various types of Hα profile, the presence (or absence) of forbidden and permitted emissions, as well as circumstellar components. Variability of spectral features of various nature is studied. Absolute luminosity, circumstellar envelope expansion rate and amplitude of pulsations are determined. The reliability of the YHG status for V1427 Aql is confirmed; manifestations of a significant dynamic instability of the upper layers of the atmosphere of ρ Cas after the 2017 ejection and stratification of its gas envelope are registered; the lack of companion in the system of the V509 Cas hypergiant is proven; a conclusion is made that the V1302 Aql hypergiant is approaching the low-temperature boundary of the Yellow Void.

A method of “self-calibration” of two sectors of the RATAN-600 radio telescope based on synchronous measurements of strong extragalactic sources, including variable ones, is proposed. The method gives refined corrections to the standard calibration of each of the telescope’s sector. It is based on the fact that ideal synchronous independent measurements of the same object should give the same results. Differences from the unity of the result of approximating the flux ratio synchronously measured at two sectors for a subsample of strong sources are considered as systematic calibration errors and used to calculate corrections that exclude these errors, and are applied to measurements of all sample objects in this observation cycle. The method was tested with RATAN-600 two sectors in meridian multifrequency measurements and can be used for independent pairs of any closely spaced antennas. In this case, the analog of RATAN-600 sector is a separate telescope. For far-spaced antennas, an additional error will be introduced due to different effects of the atmosphere and altitude of objects during synchronous observations.