Deep RATAN-600 surveys at the declination of SS 433 carried out in 1987–2000 at 7.6 and 2.7 cm

We discuss the results of deep surveys of a ±10′ strip of the sky, centered on the declination of SS 433, carried out on the Northern sector of the RATAN-600 telescope at 2.7 and 7.6 cm in 1987–2000. The survey objects are cross-identified with sources in the NVSS catalog and the corresponding two-frequency spectral indices determined. We find a decrease in the mean spectral index in the transition from objects with flux densities S ₂₁ ≥ 30 mJy to those with 15 < S ₂₁ < 30 mJy. The constructed log N — logS relation at 2.7 cm has a slope of 3/2 at flux densities ≥300 mJy and flattens at weaker flux densities. The 1.4 GHz (NVSS), 3.94 GHz (RATAN-600), and 11.11 GHz (RATAN-600) data are used to estimate the number of objects per square degree at a wavelength of 1 cm.     

Quasi-simultaneous VLBI and RATAN-600 observations of active galactic nuclei

VLBI observations of several quasars and BL Lacertae objects were carried out at 1.66 GHz in November–December 1999 using six antennas (Medvezh'i Ozera, Svetloe, Pushchino, Noto, HartRAO, and Shanghai). Maps of six sources (0420+022, 0420-014, 1308+326, 1345+125, 1803+784, and DA 193) obtained with milliarcsecond resolution are presented and discussed, together with their broad-band (1–22 GHz) spectra obtained on the RATAN-600 radio telescope at epochs close to those of the VLBI observations. Comparison of the VLBI maps with maps of these sources obtained on standard VLBI networks and with the RATAN-600 quasisimultaneous total-flux measurements indicates the reliability of the results obtained on this Low Frequency VLBI Network and the good efficiency of this network.     

A RATAN-600 Zenith-Field sky survey. Catalog of radio sources

A catalog of radio sources detected in a deep RATAN-600 survey is presented. The catalog was obtained in the region 0^h ≤ RA_2000.0 ≤ 24^h, Dec_2000.0 = 41°30′42″ ± 2′, at the declination of the bright radio source 3C 84. There were nine sessions of multi-wavelength observations at wavelengths λ = 1–55 cm, and more than 300 daily scans were accumulated at each wavelength. This is the first stage in the reduction of an extensive database accumulated by the Cosmological Gene Project. The RATAN-600 Zenith Field (RZF) catalog was obtained at the central wavelength of 7.6 cm, and contains 437 radio sources, virtually all of which have been identified with NVSS objects. Most of the flux densities for the catalog sources are above the 5σ level. Noise from faint (mainly new) background sources at a level of about 0.8 mJy has been detected. The minimum flux density of the catalog, 2.5 mJy, is comparable to the flux-density linit of the NVSS catalog. The catalog is more than 80% complete for sources with flux densities >3 mJy.     

Radio spectra of giant radio galaxies from RATAN-600 data

Measurements of the flux densities of the extended components of seven giant radio galaxies obtained using the RATAN-600 radio telescope at wavelengths of 6.25 and 13 cm are presented. The spectra of components of these radio galaxies are constructed using these new RATAN-600 data together with data from the WENSS, NVSS, and GB6 surveys. The spectral indices in the studied frequency range are calculated, and the need for detailed estimates of the integrated contribution of such objects to the background emission is demonstrated.     

A second set of RATAN-600 observations of giant radio galaxies

Results of RATAN-600 centimeter-wavelength flux-density measurements of the extended components in five giant radio galaxies are reported. The spectra of the components of these radio galaxies have been constructed using the data of the WENSS, NVSS, and GB6 surveys together with new RATAN-600 data. Spectral indices in the studied frequency range have been calculated.     

Spectral studies with the Special Astrophysical Observatory 6 m and RATAN-600 telescopes

We present optical identifications, classifications, and radio spectra for 19 radio sources from a complete sample in flux density with declinations 10°–12°30′ (J2000) obtained with the 6-m optical telescope (4000–9000 Å) and RATAN-600 radio telescope (0.97–21.7 GHz) of the Special Astrophysical Observatory. Twelve objects with redshifts from 0.573 to 2.694 have been classiffied as quasars, and two objects with featureless spectra as BL Lac objects. Four objects are emission-line radio galaxies with redshifts from 0.204 to 0.311 (one also displaying absorption lines), and one object is an absorption-line galaxy with a redshift of 0.214. Radio flux densities have been obtained at six frequencies for all the sources except for two extended objects. The radio spectra of five of the sources can be separated into extended and compact components. Three objects display substantial rapid (on time scales from several days to several weeks) and long-term variability of their flux densities.     

Physics of post-eruptive solar arcades: Interpretation of RATAN-600 and STEREO spacecraft observations

Results of simultaneous measurements of radiation fluxes from post-eruption arcades on the Sun at 171, 195, 284, and 304 ? (from STEREO spacecraft data) and at radio wavelengths (from the RATAN-600 radio telescope) are presented. An original probabilistic approach developed earlier by Urnov was used to determine the differential emission measure. This method requires no regularization, and the obtained results do not depend on the choice of the temperature grid. This approach has yielded the differential measure of emission at temperatures approximately from 0.3 to 15 MK. The subsequent calculation of thermal magnetobremsstrahlung in a multi-temperature model with the magnetic field decreasing with height produces a spectrum similar to that observed on RATAN-600. Thus, in many non-stationary events with modest powers, a thermal multi-temperature model is quite able to explain the emission of post-eruption arcade systems, and it is not necessary to invoke the emission of accelerated particles. The proposed model enables direct estimation of the ratio of the magnetic and gas pressures at the tops of post-eruption arcades, and determination of the conditions required for the origin of secondary nonstationary processes in the decay stage of the main flare.     

Search for spatial and spectral fluctuations of the cosmic microwave background radiation using the RATAN-600 radio telescope

We report the results of a search for spatial and spectral fluctuations of the cosmic microwave background in the region of the North celestial pole carried out at 6.2 cm using the RATAN-600 radio telescope in 1999–2000. The spatial spectrum is flat and has no features exceeding ΔT/T =10^?3 in a ～1 MHz frequency band for spatial periods from 0.5′ to 16′. If this estimate is adopted as an upper limit for emission associated with the first rotational transition of primordial LiH at z=90.7, we obtain an upper limit for the LiH abundance of about 3×10^?14 for protocluster masses of about 10¹³ M _⊙.     

Radio spectra of objects in the RATAN-600 RZF catalog and a population analysis of faint radio sources

Results of centimeter-wavelength RATAN-600 observations of several hundred NVSS objects with a wide range of flux densities are presented. Changes in spectral-index distributions from strong-to faint-object populations are estimated. In the transition from strong to faint radio sources, the number of steep-and ultrasteep-spectrum objects decreases and the minimum between steep-and flat-spectrum objects, which was first discovered in the 1970s, becomes less distinct. A less certain increase in the fraction of inverted-spectrum objects is also found. Comparison with theoretical models of radio-source evolution suggests that the decrease in the number of steep-and ultrasteep-spectrum objects can be naturally explained by a sharp decrease in the fraction of classical FRII radio galaxies. The decrease in the sharpness of the minimum may be due to the growing contribution from the population with spectral indices 0.7–0.5, which is usually identified with starbust galaxies. The small increase in the fraction of inverted-spectrum radio sources can be attributed to the growing number of objects with active nuclei. Our spectrum-based conclusions are confirmed by the morphology of the FIRST Catalog images. The number of radio sources associated with supermassive black holes in the Early Universe is estimated using data from the SDSS Catalog.     

Monitoring of the Blazar J0238+1636 with the RATAN-600 and RT-32 in 2014−2019

The presented observation results of the blazar J0238+1636 were obtained in: 2014–2019 with the RATAN-600 radio telescope from the Special Astrophysical Observatory of the Russian Academy of Sciences at 2.3, 4.8, 8.2, 11.2, and 21.7 GHz; and 2015–2017 with the 32-m Zelenchuk and Badary radio telescopes of the Institute of Applied Astronomy of the Russian Academy of Sciences at 4.84 and 8.57 GHz. Two flares were detected on the long-term light curve. The time scale for variability on the rising branch of the first flare is τvar = 0.5 year, and the upper limit for the linear and angular sizes of the emitting region at 21.7 GHz are 0.3 pc and 0.05 mas, respectively. The brightness temperature is Tb ≥ 2.6 × 1013 K, and the Doppler factor is δ ≥ 3. In three sets of the source’s daily observations, which lasted up to three months each, no significant variability on the day-to-day scale was found after subtracting the long-term variability. In the RT-32 data, the intraday variability (IDV) was found at a frequency of 4.84 GHz in three out of 15 sessions and at 8.57 GHz in two out of 13 sessions. The characteristic times for variability are 4−5 hours.     

Rotation of the Universe at different cosmological epochs

A step-by-step foundation for the differential character of the Universe’s rotation is presented. First, invoking the concept of spacetime foam with spin, it is reasonable to assume that the very early Universe can be described by the Dirac equation. Second, it is shown using the Ehrenfest theorem that, from a classical point of view, the early Universe can be described by the Papapetrou equations. Third, it is stressed that our Universe can perform only rotational motion. It is shown based on the spin part of the Papapetrou equations that the Universe’s rotation depends appreciably on the physical properties of a specific cosmological epoch. The rotational angular velocity is calculated for three basic cosmological epochs: the matter-dominated epoch, the transition period (from domination of matter to domination of vacuum), and the vacuum-dominated epoch.     

The theory of bypassed-isotope formation in the universe

A Fermi-gas model for the atomic nucleus in the presence of a quantizing magnetic field is considered. The energy of the magnetized neutrons is determined taking into account the Pauli paramagnetism, and the energy of the magnetized protons taking into account Landau diamagnetism and Pauli paramagnetism. To determine the characteristics of the proton-gas energy in a quantizing magnetic field, we use a model for the proton motion in which the initial energy of the proton and the magnetic field strength enable estimation of the maximum Landau quantum number. The latter characterizes the proton motion perpendicular to the direction of the magnetic field. Due to the occupation of Landau levels by protons, it is possible to estimate the kinetic energy for continuous motion along the magnetic field from zero to a certain finite value. As a result, the magnetic field of a certain strength facilitates neutron evaporation from the nucleus and increases the stability of the protons in the nucleus.     

Type Ia supernovae: Non-standard candles of the universe

We analyze the influence of the evolution of light absorption by gray dust in the host galaxies of type Ia supernovae (SN Ia) and the evolution of the mean combined mass of close-binary carbon-oxygen white dwarfs merging due to gravitational waves (SN Ia precursors) on the interpretation of Hubble diagrams for SN Ia. A significant increase in the mean SN Ia energy due to the higher combined masses of merging dwarfs should be observable at redshifts z > 2. The observed relation between the distance moduli and redshifts of SN Ia can be interpreted not only as evidence for accelerated expansion of the Universe, but also as indicating time variations of the gray-dust absorption of light from these supernovae in various types of host galaxies, observational selection effects, and the decreasing mean combined masses of merging degenerate dwarfs.     

Deep surveys and the nonthermal noise of radio telescopes

The paper presents an analysis of catalogs of discrete radio sources and the results of deep surveys carried out with angular resolutions to 1.5″ and limiting flux densities to 9 μJy at frequencies from 80 MHz to 8.5 GHz using large radio telescopes around the world. We consider the influence on the sensitivity of a radio telescope of the nonthermal noise associated with variations in the total flux due to fluctuations in the number of unresolved sources with fluxes lower than the observed value that fall in the main lobe of the antenna beam when the direction in which the receiver is pointed is changed (the first component), and also due to sources with fluxes higher than the observed value that arrive in the scattering region of the telescope (the second component). With growth in the sensitivity and resolution of a telescope, the second component of this nonthermal noise determines to an appreciable extent the limiting capability of the telescope for carrying out deep surveys. We estimate the number of antenna beams per source that are required to reach a specified sensitivity in deep surveys. The results of our calculations are compared with data derived from catalogs and numerous surveys.     

Effective curvature of the universe in observations of distant objects

We analyze the propagation of light in a universe with density inhomogeneities, which, as was first demonstrated by Zel’dovich, systematically affect the angular sizes and apparent magnitudes of distant objects. The Zel’dovich effect can be represented in terms of an effective curvature, which is proportional to the magnitude of the inhomogeneities. We estimate the effective curvature, radius of curvature, and mean distance between conjugate points for the cases when the density inhomogeneities are taken to be stars in the Galaxy, galaxies, and clusters of galaxies. We discuss the possibility of detecting the Zel’dovich effect using modern astronomical data.     

Hydrogen subordinate line emission at the epoch of cosmological recombination

The balance equations for the quasi-stationary recombination of hydrogen plasma in a black-body radiation field are solved. The deviations of the excited level populations from equilibrium are computed and the rates of uncompensated line transitions determined. The expressions obtained are stable for computations of arbitrarily small deviations from equilibrium. The average number of photons emitted in hydrogen lines per irreversible recombination is computed for plasma parameters corresponding to the epoch of cosmological recombination.     

Structural isomerization and the evolution of the molecular world during the early universe evolution

Basic tendencies and relations in the origin of the molecular world during the early evolution of the universe imply the conclusion that the key factor in the synthesis of complicated molecules as a consequence of the fluctuating aggregation of atoms and simplest compounds was the ability of the same group of atoms to generate molecules in the form of a vast number of diverse structural isomers. The problem of the complementarity of random and deterministic processes is discussed.     

Integration of geodetic and geotechnical deformation surveys in the geosciences

Ground movement studies can utilize information from conventional geodetic surveying, photogrammetry, and geotechnical measurements of strain, tilt, etc. Each method alone cannot yield a complete picture of the deformation. However, each is complemented by the others. Hence, their integration in a simultaneous analysis in space and in time is advocated. An integrated analysis is readily accommodated by a generalized method of deformation analysis devised by the authors. Any number of measurements of any type can be considered in any fashion of modelling with full statistical assessment of the modelling and of derived characteristics. Such an integration is illustrated using data from a coal mining area in rugged mountainous terrain of western Canada. Conventional terrestrial geodetic methods connected 15 stations. Displacements from an additional 29 points were obtained from aerial photogrammetry. Biaxial tiltmeters continuously measured ground tilts at 3 stations. A surface of subsidence for the whole area was modelled with the graphical depiction in three dimensions.     

The vacuum component of the Universe (cosmological constant) should evolve

The evolution of the vacuum component of the Universe is studied in both the quantum and classical regimes. Our Universe has emerged as a result of a tunneling process, beginning with an oscillating mode and passing on to a Friedmann mode, and it very probably had a high symmetry for the Planck parameters. In the first fractions of a second (the quantum regime), as it cooled, the vacuum component of the Universe lost its high degree of symmetry due to phase transitions; i.e., its positive energy density was subject to negative contributions from quantum field condensates (by 78 orders of magnitude). After the last (quark-hadron) phase transition, the vacuum energy ??froze.?? At this time (10^?6 s), the vacuum energy density can be calculated using the formula of Zel??dovich and substituting the mean values of the pseudo-Goldstone boson (??-mesons) masses characterizing the chromodynamic vacuum. Chiral symmetrywas lost at that time. The dynamics of the equilibrium vacuum after its ??hardening?? is considered using the holographic principle. During the next 4 × 10¹⁷ s (the classical regime), the vacuum component of the Universe was reduced by 45 orders of magnitude due to the creation of new quantum states during its expansion. It is possible to solve the cosmological-constant problem using the holographic principle, since the 123 problematic orders of magnitude disappear in usual physical processes. The vacuum energy density is also calculated in the classical regime to a redshift of 10¹¹ using a ??cosmological calculator.??     

Gravity and magnetic surveys and interpretation in the northern part of the K-G basin

The gravity and magnetic data along three profiles across the northern part of the K-G basin have been collected and the data is interpreted for basement depths. The first profile is taken from Gadarada to Yanam covering a distance of 60 km and the second starts from Zangareddiguddem to Samathkur covering a distance of 110 km and the third is from Kotturu to Biyyapuppa covering a distance of 100 km. The gravity lows and highs have clearly indicated various sub-basins and ridges. The density logs from ONGC, Chennai, show that the density contrast decreases with depth in the sedimentary basin, and hence, the gravity profiles are interpreted using variable density contrast with depth. From the Bouguer gravity anomaly, the residual anomaly is constructed by graphical method correlating with well data, sub-surface geology and seismic information. The residual anomaly profiles are interpreted using polygon model. The maximum depths to the khondalitic basement are obtained as 5.61km, 6.46 km and 7.45 km for the first, second and third profiles respectively. The regional anomaly is interpreted as Moho rise towards coast. The aeromagnetic anomaly profiles are also interpreted for charnockite basement below the khondalitic group of rocks using prismatic models.