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卷 63, 编号 4 (2019)

Article

On the Inner Structure of Virialized Clusters

Del Popolo A., Lee X.

摘要

In the present paper, we studied the correlations among different quantities in the clusters of galaxies observed by Newman et al. We found an anti-correlation among the slope α, the effective radius, Re, and a correlation among the core radius rcore and Re. Moreover, the mass in 100 kpc (mainly dark matter) is correlated with the mass inside 5 kpc (mainly baryons). The previous correlations can be understood in a two phase formation model: a first dissipative phase forming the proto-BCG and a second dissipationless phase, in which the inner density profile is flattened by the interaction of baryonic clumps and the DMhalo through dynamical friction (DF).

Astronomy Reports. 2019;63(4):249-262
pages 249-262 views

Strong Shock in a Uniform Expanding Universe. Approximate and Exact Solutions of Self-Similar Equations

Bisnovatyi-Kogan G., Panafidina S.

摘要

Self-similar solution is obtained for propagation of a strong shock, in a flat expanding dusty Friedman universe. Approximate analytic solution was obtained earlier, using relation between self-similar variables, equivalent to the exact energy conservation integral, which was obtained by L.I. Sedov for the strong explosion in the static uniform medium. Here, numerical integration of self-similar equation is performed, providing an exact solution of the problem, which is rather close to the approximate analytic one. The differences between these solutions are most apparent in the vicinity of the shock. For a polytropic equation of state, self-similar solutions exist in a more narrow interval of the adiabatic power than in the static case.

Astronomy Reports. 2019;63(4):263-273
pages 263-273 views

The Chemical Composition of Globular Clusters of Different Nature in Our Galaxy

Marsakov V., Koval’ V., Gozha M.

摘要

A catalog of Galactic globular clusters has been compiled and used to analyze relations between the chemical and kinematic parameters of the clusters. The catalog contains positions, distances, luminosities, metallicites, and horizontal-branch morphology indices for 157 globular clusters, as well as space velocities for 72 globular clusters. For 69 globular clusters, these data are suppleented with the relative abundances of 28 chemical elements produced in various nuclear-synthesis processes, taken from 101 papers published between 1986 and 2018. The tendency for redder horizontal branches in lowmetallicity accreted globular clusters is discussed. The discrepancy between the criteria for cluster membership in the thick-disk and halo subsystems based on chemical and kinematic properties is considered. This is manifest through the fact that all metal-rich ([Fe/H] > −1.0) clusters are located close to the center and plane of the Galaxy, regardless of their kinematic membership in particular Galaxy subsystems. An exception is three accreted clusters lost by a dwarf galaxy in Sagittarius. At the same time, the fraction of more distant clusters is high among metal-poorer clusters in any kinematically selected Galactic subsystem. In addition, all metal-rich clusters whose origins are related to the same protogalactic cloud are located in the [Fe/H]–[α/Fe] diagram considerably higher than the strip populated with field stars. All metal-poor clusters (most of them accreted) populate the entire width of the strip formed by high-velocity (i.e., presumably accreted) field stars. Stars of dwarf satellite galaxies (all of them being metal-poor) are located in this diagram much lower than accreted field stars. These facts suggest that all stellar objects in the accreted halo are remnants of galaxies with higher masses than those in the current environment of the Galaxy. Differences in the relative abundances of α-process elements among stellar objects of the Galaxy and surrounding dwarf satellite galaxies confirmthat the latter have left no appreciable stellar traces in the Galaxy, with the possible exception of the low-metallicity cluster Rup 106, which has low relative abundances of α-process elements.

Astronomy Reports. 2019;63(4):274-288
pages 274-288 views

A Star of Vacuum-like Matter

Novikov I., Novikov D.

摘要

A model of a star consisting of vacuum-like matter is constructed in the framework of general relativity. Its stability and other physical properties are analyzed. This stellar model is compared with cosmological models consisting of the same vacuum-likematter with a pressure equal to the energy density but with the opposite sign.

Astronomy Reports. 2019;63(4):289-292
pages 289-292 views

The Concept of a Multi-Functional Astronomy Complex and Dynamically Integrated Database Applied to Multi-Channel Observations with the MASTER Global Network

Lipunov V., Vladimirov V., Gorbovskoi E., Kuznetsov A., Zimnukhov D., Balanutsa P., Kornilov V., Tyurina N., Gress O., Vlasenko D., Gabovich A., Yurkov V., Kuvshinov D., Senik V.

摘要

The concept of a multi-functional astronomical complex as applied to robotic astronomy networks and systems is formulated. The practical realization of this concept in the MASTER global network of robotic telescopes of Moscow State University is described. The dynamically integrated MASTER database, which transforms a network of robotic telescopes into a robotic network, is described. Real, multi-channel astronomical observations obtained on the MASTER global network are used to show the effective application of this concept. The MASTER global network is continuously participating in multi-wavelength and multi-channel observations aimed at studying astrophysical sources located in extreme conditions, including the sources of gravitational waves registered by the LIGO/VIRGO detectors, of high-energy neutrinos detected by IceCube and ANTARES, and of fast radio bursts (FRBs) and gamma-ray bursts (GRBs). The MASTER network provided the most extensive survey of the first error field for the LIGO gravitational-wave outburst GW 150914 (5000 square degrees) and carried out the first independent localization of the gravitational-wave event GW170817. TheMASTER network has also discovered more than 1600 optical transients with various physical natures. Data obtained with the MASTER network have been used to provide pointing information to major ground-based and space-based telescopes.

Astronomy Reports. 2019;63(4):293-309
pages 293-309 views

A 12-Year Periodicity in the Pulse Arrival Times for the Pulsar PSR B0943+10

Starovoit E., Suleymanova S.

摘要

An analysis of observations obtained over 26 years beginning in 1992 have indicated the appearance of sinusoidal variations with a period of about 12 years in the residual deviations of the pulse arrival times (PATs) for the pulsar PSR B0943+10. This behavior in the PAT residuals could be due to the influence of a planet orbiting the pulsar. These observations were carried out on the Large Scanning Antenna of the Pushchino Radio Astronomy Observatory at 112 MHz.

Astronomy Reports. 2019;63(4):310-315
pages 310-315 views

Variability of the Blazar J1504+1029 on Timescales from Hours to Years

Konnikova V., Kharinov M., Ipatov A., Ipatova I., Mardyshkin V., Mingaliev M.

摘要

The results of observations of the blazar J1504+1029 (PKS 1502+106, OR 103), obtained in 2000–2018 on the RATAN-600 radio telescope of the Special Astrophysical Observatory at 2.3, 3.9 (4.7), 7.7 (8.2), 11.2, and 21.7 GHz and on the 32-m Zelenchuk and Badary radio telescopes of the Quasar-KVO complex of the Institute of Applied Astronomy of the Russian Academy of Sciences at 5.05 and 8.63 GHz are presented. The long-term variability is studied, as well as variability on time scales from several days to several weeks and intraday variability (IDV). The long-term light curves are correlated at all frequencies and show continuous activity, against which three flares with their maxima in 2002, 2009, and 2018 are distinguished. The time scale for variability of the flare in 2009 is τvar ≈ 1 year. At 21.7 GHz, the linear size of the emitting region is R ≤ 0.3 pc, its angular size is θ ≤ 0.05 mas, its brightness temperature is Tb ≥ 2 × 1014 K, and the Doppler factor is δ ≥ 5.8. The flare with its maximum in 2018 has a long rising branch at 21.7 GHz: τvar = 3.2 years, linear size R ≤ 1.1 pc, angular size θ ≤ 0.17 μas, brightness temperature Tb ≥ 2.2 × 1012 K, and Doppler factor δ ≥ 2.8. Among eleven sets of daily observations of the source over 75–120 days in 2000–2017, variability was detected in eight data sets at two to four frequencies with characteristic time scales of 4–30 days. In seven data sets, the variability is due to one to three cyclic processes with characteristic time scales τacf = 4−30d. The spectral indices of the variable components in different years vary from αvar = −1.6 to +1.8. In at least four data sets, the variability is due to processes in the source itself. In this case, at 21.7 GHz, the apparent linear size of the emitting region is ≤4000 AU, the angular size is θ ≤ 3.5 μas, the brightness temperature is Tb ≥ 3 × 1014 K, and the Doppler factor is δ ≥ 14. In the 2004 data set, the variability has an “ anti-flare” form, with the flux density of the variable component falling at high frequencies. Thirty-six successful sessions were conducted on the 32-m telescopes at 8.63 GHz, and 16 at 5.05 GHz. IDV was detected in 17 sessions at 8.63 GHz and in three sessions at 5.05 GHz, with the IDV being detected mainly near flare maxima.

Astronomy Reports. 2019;63(4):316-342
pages 316-342 views

Catalog of Supermassive Black Holes for Interferometric Observations

Mikheeva E., Lukash V., Repin S., Malinovskii A.

摘要

The paper presents a catalog of supermassive black holes (SMBHs) sharpened for interferometric observations at millimeter and submillimeter wavelengths, based on open sources. The catalog includes the object’s name, coordinates, angular size, and mass, the angular size of the gravitational radius of the SMBH, and the integrated radio flux associated with the radiosource concluding the SMBH at 20−900 GHz, planned for the Event Horizon Telescope, the future space mission Millimetron, and others. The catalog is intended for use during planning of interferometric observations of SMBH shadows.

Astronomy Reports. 2019;63(4):343-352
pages 343-352 views