Modeling the generation of the magnetic field in NGC 5775

A model for the generation of large-scale magnetic fields is constructed for the galaxy NGC 5775, in which the magnetic field has the form of a dipolar dynamo wave propagating along the galactic disk. The excitation of such a mode, which is unusual for galactic dynamos, can be explained by the strong variation of the galactic rotation with height above the plane of symmetry of the galactic disk.     

The nature of active radio galaxies in the cluster A569

We investigate the nature of bright radio sources with known radio spectra in the direction of the nearby cluster of galaxies A569 (z=0.0193). The optical identifications of the sources show that 45% of these radio sources are associated with compact galaxies. A substantial fraction of these galaxies have active nuclei, with the radio emission concentrated toward the galactic center. Some of the cluster galaxies have radio halos, with appreciably weaker radio powers and spectral indices α=0.95±0.2. We compute the magnetic fields in the nuclei and halos of the galaxies for the adopted distance to A569. As expected, the magnetic fields in the galactic halos make a smooth transition to the intergalactic field, while the magnetic fields in the central regions of the galaxies rise sharply toward the nucleus.     

The fast dynamo in interstellar turbulence

The α effect and coefficient of eddy diffusivity are calculated for the magnetic field in a random flow with recovery. Such a flow loses its memory abruptly at random times that form a Poisson flow of events. Interstellar turbulence sustained by supernova outbursts is one physical realization of such a flow. The growth rates and configurations of large-scale galactic magnetic fields for this situation are close to those predicted by simple galactic dynamo models. At the same time, the model of a flow with recovery makes it possible to trace the role of the effective “forgetting” of correlations. The presence of this forgetting distinguishes interstellar turbulence from other types of random flows.     

The luminosity function of narrow-line Seyfert 1 galaxies based on SDSS data (DR7)

Luminosity functions of Seyfert 1 active galactic nuclei in the [OIII] λ5007 Å forbidden line are derived from Sloan Digital Sky Survey data (Data Release 7). Special attention is paid to the peculiar class of narrow-line Seyfert 1 (NLSy1) galaxies, whose optical broad, permitted lines are relatively narrow (FWHM ≤ 2000 km/s). A new technique for obtaining an emission-line luminosity function that is able to take into account density variations due to the large-scale structure of the Universe, among other factors, is discussed. The derived luminosity functions are compared with those for other types of active galactic nuclei using available published data. The X-ray luminosity function predicted using our data demonstrates good agreement with observations.     

Magnetic tunnels (wormholes) in astrophysics

We consider models of a wormhole (i) maintained by an electromagnetic field, taking into account quantum vacuum corrections to the equation of state, (ii) maintained by a combination of the magnetic field and phantom energy, with a spherically symmetrical equation of state, and (iii) with a magnetic field and phantom matter with an anisotropic equation of state. It is shown that the quantum corrections and the density and exoticity of phantom energy or matter can be as small as is desired. For an external observer, the entrance to the tunnel appears to be a magnetic monopole of macroscopic size. The accretion of ordinary matter onto the entrance to the tunnel may result in the formation of a black hole with a radial magnetic field. We consider the possibility that some active galactic nuclei and Galactic objects may be current or former entrances to magnetic wormholes. We consider the possible existence of a broad mass spectrum for wormholes, from several billion solar masses to masses of the order of 2 kg. The Hawking effect (evaporation) does not operate in such objects due to the absence of a horizon, making it possible for them to be retained over cosmological time intervals, even if their masses are smaller than 10¹⁵ g. We also discuss a model for a binary system formed by the entrances of tunnels with magnetic fields, which could be sources of nonthermal radiation and γ-ray bursts.     

Study of the physical conditions in active galactic nuclei. A method for estimating the physical parameters of radio sources

A new method for estimating the physical parameters of active galactic nuclei involving the analysis of observations of the compact radio sources in them is proposed. The method is based on an inhomogeneous model for a synchrotron radio source. Theoretical spectra of the radio sources are obtained via numerical solution of the transfer equation. Due to the paucity of observational data, only interval estimates of the magnetic field strength and the energy densities of the magnetic field and relativistic particles can be obtained. A mechanism for the formation of flat radio spectra is proposed.     

银河旋臂、地核环流与地球大冰期

地球在其约４６亿年的生命史中，多次出现大冰期，关于其形成原因是地球科学家研究的热门课题。促使地球系统演化的力源主要来自哪一圈层？气体具有最大的激活能，但大气圈仅占地球总质量的１０－６，它不可能是主要圈层。固态的激活能最低，下地幔和地内核亦不大可能在地球系统演化中扮演主要角色。地球外核是液态，具有较高的激活能，它约占现代地球系统总质量的３０％，故可认为它是地球系统演化的主要活动圈层。作为旋转地球上的流体，外核环流存在着两种极端流型：一是“地转流型”，其速度场是二维场，垂直运动很弱（以下简称为Ｇ型）；二是“强对流型”，当Ｅｌｓｓａｓｅｒ数≥１时，流场的二维几乎完全被Ｌｏｒｅｎｚ力所破坏，对流充满整个地核（以下简称Ｃ型）。文章在事实分析的基础上提出了地球大冰期形成的如下假说：当地球背景磁场与银河旋臂磁场极性符号相同时，外磁场将激发地球外核环流转为Ｃ型，引起地壳和地幔强烈的垂直运动（强造山运动），致使大气热机效率亦大为提高，高纬地区强降温，这是大冰期形成的根本原因。这一假说的逆表述，即当地球背景磁场与银河旋臂磁场极性相反时，地核环流将转向Ｇ型，地壳表面将主要是“夷平作用”，致使大气热机效率亦降低，行星风系减弱，高纬?     

Semi-permeable wormholes and the stability of static wormholes

Physical processes arising when an impermeable wormhole is irradiated by self-gravitating, exotic radiation are considered. It is shown that, in this case, the conditions required for the passage of signals fromanother universe into our own arise only in our Universe, whereas signals cannot pass through the wormhole in the opposite direction. Such wormholes are called semi-permeable. The stability of a static wormhole filled with radial magnetic field and exotic dust with a negative energy density is also considered.     

Early formation of galaxies induced by clusters of black holes

A model for the formation of supermassive black holes at the center of a cluster of primordial black holes is developed. It is assumed that ～10^?3 of the mass of the Universe consists of compact clusters of primordial black holes that arose as a result of phase transitions in the early Universe. These clusters also serve as centers for the condensation of dark matter. The formation of protogalaxies with masses of the order of 2 × 10⁸ M _⊙ at redshift z = 15 containing clusters of black holes is investigated. The nuclei of these protogalaxies contain central black holes with masses ～10⁵ M _⊙, and the protogalaxies themselves resemble dwarf spherical galaxies with their maximum density at their centers. Subsequent merging of these induced protogalaxies with ordinary halos of dark matter leads to the standard picture for the formation of the large-scale structure of the Universe. The merging of the primordial black holes leads to the formation of supermassive black holes in galactic nuclei and produces the observed correlation between the mass of the central black hole and the bulge velocity dispersion.     

RadioAstron and millimetron space observatories: Multiverse models and the search for life

The transition from the radio to the millimeter and submillimeter ranges is very promising for studies of galactic nuclei, as well as detailed studies of processes related to supermassive black holes, wormholes, and possible manifestations of multi-element Universe (Multiverse) models. This is shown by observations with the largest interferometer available—RadioAstron observatory—that will be used for the scientific program forMillimetron observatory. Observations have also shown the promise of this range for studies of the formation and evolution of planetary systems and searches for manifestations of intelligent life. This is caused by the requirements to use a large amount of condensedmatter and energy in large-scale technological activities. This range can also be used efficiently in the organisation of optimal channels for the transmission of information.     

Structure and Features of the Galactic Magnetic-Field Reversals Formation

At the present time, the induction of several microgauss in large-scale fields of the Galaxy has been repeatedly confirmed. There are numerous arguments in favor of the fact that the magnetic field exhibits so-called reversals associated with a direction change from one region to another. Such configurations are allowed in the nonlinear equations context of the dynamo theory, which describes the large-scale magnetic-field evolution. In the present study, reversals are modeled using the so-called no-z approximation based on the fact that the galactic disk is sufficiently thin. The magnetic field generation that exhibit both single and double sign changes with distance from the center is observed. From an observational point of view, one of the main methods for studying magnetic fields is to gauge the Faraday rotation measure of radio waves coming from pulsars. Its value can characterize the integral magnitude of the magnetic field, and the sign indicates its direction. A study of the pulsar distribution with large Faraday rotation measures ($$\left| {RM} \right| > 200$$ rad/m2) is presented. The results indicate that there is a region of $$4.8\;{\text{kpc}} < r < 7.3\;{\text{kpc}}$$ in the Galaxy in which the magnetic field is oriented counterclockwise. At the ring edges, the magnetic field reverses its direction. These results are in close agreement both with theoretical concepts and other studies dedicated to the structure observations of the magnetic field in the Galaxy.     

The magnetic-field structure in a stationary accretion disk

The magnetic-field structure in regions of stationary, planar accretion disks around active galactic nuclei where general-relativistic effects can be neglected (from 10 to 200 gravitational radii) is considered. It is assumed that the magnetic field in the outer edges of the disk, which forms in the magnetosphere of the central black hole during the creation of the relativisitic jets, corresponds to the field of a magnetic dipole perpendicular to the plane of the disk. In this case, the azimuthal field component B_φ in the disk arises due to the presence of the radial field B_ρ and the azimuthal velocity component U_φ. The value of the magnetic field at the inner radius of the disk is taken to correspond to the solution of the induction equation in a diffusion approximation. Numerical solutions of the induction equation are given for a number of cases.     

银河年和地质年代表

根据地洼学说关于地壳演化的新理论,将地球置于银河系各级引力场研究,发现银河年与地球绕日运行周期(年)有许多相似之处,后者控制了地球上短期的生物兴衰和四季交替,前者是引起地球上长期冷热变化,导致全球的生物质变进化、冰川活动及海侵海退等循银河年周期发生的根本原因。银河年是建立理想地质年代表的基础,每一个银河年就是一个代。依目前天文观测及全球生物质变进化和冰期资料来看,银河年时距以260 Ma为宜。本文据此提出了一个新的地质年代表。     

Polarimetric differences between Schwarzschild and Kerr black holes in active galactic nuclei

If the linear polarization of the optical emission of active galactic nuclei (AGNs) arises in magnetized accretion disk (the Milne problem), the degree of polarization should depend strongly on the spin of the central black hole. For the same black hole luminosities and masses, the polarization is substantially higher for rotating Kerr than for non-rotating Schwarzschild black holes. Statistically, this means that the majority of AGNs displaying appreciable linear polarization should have Kerr black holes. The spin dependence of the polarization is due to the fact that the radius of the innermost stable circular orbit r _isco depends on the spin—this radius is three gravitational radii for a Schwarzschild black hole, and a factor of six smaller for a rapidly rotating black hole. This means that the magnetic field in the region of emergence of the optical emission, which decreases with distance from r _isco , is higher for a non-rotating than for a rapidly rotating black hole. This higher magnetic field gives rise to strong Faraday depolarization, explaining the effect considered here.     

Study of the physical conditions in active galactic nuclei. Physical conditions in the cores of two nearby radio galaxies

We have carried out a search for compact radio sources in the cores of 16 nearby radio galaxies. We detected compact components in four radio galaxies, and found upper limits for the flux density in compact components in ten radio galaxies. VLBI observations enabled the detection of a turnover in the spectra of the two nearby radio galaxies 3C 111 and 3C 465. Using a method based on an inhomogeneous model for a synchrotron source, we estimate the magnetic-field strength and the energy densities in the magnetic field and relativistic electrons in the cores of these radio galaxies. Strong inhomogeneity in the distribution of the magnetic fields in the cores of 3C 111 and 3C 465 is implied by our analysis. The magnetic-field strengths in the central regions of these galactic nuclei, on scales of ～0.1 pc, exceed the mean strength by four to five orders of magnitude, and lie in the range 10² G < H < 10⁴ G.     

The sequence of geological events and the dynamics of the Milky Way galaxy

Present‐day galactic data permit the construction of a galactic model in which the galactic gravitational field is described by a gravitational function rather than the Newtonian gravitational “constant” G. The concept of this empirical gravitational function, which is based on galactic orbital velocity data, envisages G as a function of time and space. In this model the interaction of this gravitational function, which has rotational symmetry in the galactic plane, and the slightly elliptical galactic orbit of the solar system results in a systematic variation of G. This interaction specifies a simple galactic time‐scale which can be conveniently compared with events of the geological time‐scale. For reasons of galactic evolution and modifying effects due to suspected changes of mass distributions in the universe with the passage of time, which are classed here under the Dirac‐Jordan Effect, such a comparison is initially restricted to the past 1#fr1/4> cosmic years, or 350 million years. The problems in extending such a comparison to 8 cosmic years are discussed, and such an extension seems promising, but it is hampered by the paucity of geological and geophysical data from the lower Palaeozoic and the Precambrian and the present uncertainties in regard to galactic evolution.

“Worldwide” statistical maxima and minima of the following geological criteria disclose an episodic correlation with the variation of G and the rates of change of G during the past 350 million years, as specified by this galactic model. It is possible to interpret this correlation in terms of accepted geological principles and concepts in most cases. The following geological phenomena are considered in this comparison of the galactic and geological time‐scales for the past 350 million years.

Period boundaries of the stratigraphic system     

Seyfert nuclei as sources of ultrahigh-energy cosmic rays

Particles can be accelerated to ultrahigh energies E≈10²¹ eV in moderate Seyfert nuclei. This acceleration occurs in shock fronts in relativistic jets. The maximum energy and chemical composition of the accelerated particles depend on the magnetic field in the jet, which is not well known; fields in the range ～5–1000 G are considered in the model. The highest energies of E≈10²¹ eV are acquired by Fe nuclei when the field in the jet is B≈16 G. When B～(5–40) G, nuclei with Z<10 are accelerated to E≤10²⁰ eV, while nuclei with Z≥10 acquire energies E≥2×10²⁰ eV. Only particles with Z≥23 acquire energies E≤10²⁰ eV when B～1000 G. Protons are accelerated to E<4×10¹⁹ eV, and do not fall into the range of energies of interest for any magnetic field B. The particles lose a negligible amount of their energy in interactions with infrared photons in the accretion disk; losses in the thick gas-dust torus are also negligible if the luminosity of the galaxy is L≤10⁴⁶ erg/s and the angle between the normal to the galactic plane and the line of sight is sufficiently small, i.e., if the axial ratio of the galactic disk is comparatively high. The particles do not lose energy to curvature radiation if their deviations from the jet axis do not exceed 0.03–0.04 pc at distances from the center of R≈40–50 pc. Synchrotron losses are small, since the magnetic field frozen in the galactic wind at R≤40–50 pc is directed (as in the jet) primarily in the direction of motion. If the model considered is valid, the detected cosmic-ray protons could be either fragments of Seyfert nuclei or be accelerated in other sources. The jet magnetic fields can be estimated both from direct astronomical observations and from the energy spectrum and chemical composition of cosmic rays.     

Solar modulation of galactic cosmic rays in the three-dimensional heliosphere according to meteorite data

Cosmogenic radionuclides with distinctive half-lives from chondritic falls were used as natural detectors of galactic cosmic rays (GCR). A unique series of uniform data was obtained for variations in the integral gradients of GCR with a rigidity of R > 0.5 GV in 1955–2000 on heliocentric distances of 1.5–3.3 AU and heliographic latitudes between 23° S and 16° N. Correlation analysis was performed for the variations in GCR gradients and variations in solar activity (number of sunspots, SS, and intensity of the green coronal line, GCL), the intensity of the interplanetary magnetic field (IMF), and the inclination of the heliospheric current sheet (HCS). Distribution and variations of GCR were analyzed in 11-year solar cycles and during a change in 22-year magnetic cycles. The detected dependencies of GCR gradients on the intensity of IMF and HCS inclination provided insight into the differences in the processes of structural transformation of IMF during changes between various phases of solar and magnetic cycles. The investigated relationships lead to the conclusion that a change of secular solar cycles occurred during solar cycle 20; moreover, there is probably still an increase in the 600-year solar cycle, which can be among the major reasons for the observed global warming.     

The cosmological constant (a modern view)

We briefly discuss a modern view of the cosmological constant. It is suggested that the cosmological constant was “hardened” at E ～ 150 MeV after the latest (quark-gluon) phase transition. Until this energy was reached, the vacuum component of the Universe evolved (decreased) in a series of discontinuous jumps; i.e., condensates of quantum fields made negative contributions to its positive energy density. This was the quintessence period of the evolution of the Universe, when it underwent an intense loss of symmetry during the first fractions of a microsecond of its existence. However, this point of view is not without criticism, and other approaches are considered. In particular, the small value of the cosmological constant and its ability to accelerate the expansion of the Universe is of great interest. Although all available data on the cosmological constant were recently summarized and classified by S. Nobbenhuis, no satisfactory solution to this problemhas been reached, and this represents a major difficulty for progress in quantum-gravity theory and cosmology. We briefly discuss the possibility for stars to be formed from dark energy (vacuum stars) and the extension of holographic ideas to the entire Universe. We also consider the possibility of solving the problem of the cosmological constant by introducing a universal wave function; i.e., quantum decoherence, which implies the rejection of the Copenhagen interpretation of quantum mechanics and the acceptance of H. Everett’s point of view.     

Formation of large-scale dust lanes in spiral arms of galaxies

We consider the interaction of interstellar dust grains with a galactic shock in the gaseous component. Typical parameters of dust grains and spiral density waves imply that the formation of large-scale dust lanes at the front of a galactic shock is possible only in models taking into account a self-focusing phenomenon. In the case of an isothermal flow of interstellar gas through a spiral arm in a model with a gaseous disk of variable thickness, dust lanes can be projected onto the region of increased gas density, although this is not associated with a galactic shock. The dust density peak derived from the classical model of a galactic shock (isothermal flow and a constant thickness of the gaseous disk) is appreciably shifted downstream of the gas flow, so that it does not outline the gas density maximum.