Yu. N. Parijskij

The software system ‘evolution of radio galaxies’

Abstract The project of the informational system creation on the problem of evolution of radio galaxies is described. This system, which is currently being developed, will allow a user to operate with simulated curves of spectral energy distributions (SED) and to estimate ages and red-shifts by photometrical data. Authors use SEDs of several models (GISSEL96 (Bruzual, Charlot, 1996), PEGASE (Fioc, Rocca-Volmerange, 1996) and Poggianti (1996)) for different types of galaxies. Planned modes of access, formats of output result and additional functions are described.

Properties of one-dimensional sections of WMAP maps at the declination δ = 41°

One-dimensional sections of WMAP maps—ILC and background components (synchrotron, free-free radiation and dust emission) are investigated and their correlation properties on various angular scales are analyzed. Sections of the ILC map are found to correlate significantly with the maps of Galactic background components at the δ = 41° declination of RATAN-600 survey. The confidence level of the correlations found is estimated by analyzing random realizations of the Gaussian process that describes the microwave background. A method for identifying correlated intervals from maps on the sphere as a function of angular scale is proposed. This method can be used to search for non-Gaussian features (spots) found in the distribution of microwave background and radio sources in the same coordinate areas. The approach described can also be used to search for such non-Gaussian sources in observational programs performed on the radio telescope RATAN-600.

Investigation of the RCR catalog sources in the millimeter and submillimeter ranges based on the Planck mission data

We have studied the regions of the microwave background radiation maps of the Planck experiment in the neighborhood of the RCR catalog radio sources. From the processed data for bright radio sources in the microwave range, we plotted the calibration curves which allow the brightness of the objects to be measured. For the first time, for 117 objects we obtained estimates of flux density at the millimeter and submillimeter waves, prepared the spectra, conducted identification, and gathered available information from databases. Faint microwave sources, difficult to clear out, additionally contribute to the secondary anisotropy at angular scales smaller than 7′.

The field of view and flux sensitivity of RATAN-600

The refined data on the diffraction scattering of RATAN-600 allowed the telescope field of view to be increased substantially at large elevations. Amethod, which can be used to reconstruct the parameters of the sources passing at angular distances fromthe beamaxis that are several dozen times greater than the half-power width of the beam, is analyzed. The knowledge about wide scattering of RATAN-600 allowed the noise from background radio sources at zenith to be reduced by one order of magnitude and flux sensitivity of the radio telescope to be increased by the same factor without resorting to two-dimensional mapping. Methods for cleaning one-dimensional records of the RZF survey are suggested that use model scans based on the data of the NVSS survey and MHAT filtering. The latter proved to be an especially efficient tool for suppressing sky noise and identifying sources in the central section of the survey. The flux sensitivity of RATAN-600 is estimated with new opportunities taken into account.

Correlation properties of the maps of the NVSS survey and WMAP ILC

In this paper we study one-dimensional sections of the maps of WMAP ILC and of the NVSS survey on scale lengths of 0.75, 3, 4.5, and 6.75 degrees and analyze the correlation properties of the sections. On these maps we identify the domains where the absolute value of the correlation coefficient exceeds 0.5. The catalog of such domains is presented. It is shown that the number of the domains agrees with the number of such domains on simulated maps and this fact may be indicative of just statistical agreement of the arrangement of the domains considered.

Small-scale galactic emission fluctuation observations with RATAN-600 radio telescope

We present the estimates of Galactic synchrotron and free-free emission power at intermediate and small scales (500 < l < 1000, 20′ < θ < 40′), based on the RATAN-600 radio telescope observations (SAO RAS). The observations were conducted in the frequency range of 2.3–11.2 GHz using the transit scan mode, in the declination range of 40.7° s δ < 42.3°. The power spectrum estimates of synchrotron and free-free components were obtained. They can be further used in the data processing stage of the high-resolution cosmological experiments like Planck.

Multi-frequency survey of background radiations of the Universe. The “Cosmological Gene” project. First results

The results of the first stage of the “Cosmological Gene” project of the Russian Academy of Sciences are reported. These results consist in the accumulation of multi-frequency data in 31 frequency channels in the wavelength interval 1–55 cm with maximum achievable statistical sensitivity limited by the noise of background radio sources at all wavelengths exceeding 1.38 cm. The survey region is determined by constraints 00h < RA < 24h and 40°30′ < DEC < 42°30′. The scientific goals of the project are refined in view of recent proposals to use cosmological background radiation data for the development of a unified physical theory. Experimental data obtained with the RATAN-600 radio telescope are used to refine the contribution of the main “screens” located between the observer and the formation epoch of cosmic background radiation (z = 1100). Experimental data for synchrotron radiation and free-free noise on scales that are of interest for the anisotropy of cosmic microwave background are reported as well as the contribution of these noise components in millimeter-wave experiments to be performed in the nearest years. The role of dipole radio emission of fullerene-type dust nanostructures is shown to be small. The most precise estimates of the role of background radio sources with inverted spectra are given and these sources are shown to create no serious interference in experiments. The average spectral indices of the weakest sources of the NVSS and FIRST catalogs are estimated. The “saturation” data for all wavelengths allowed a constraint to be imposed on the Sunyaev-Zeldovich noise (the SZ noise) at all wavelengths, and made it possible to obtain independent estimates of the average sky temperature from sources, substantially weaker than those listed in the NVSS catalog. These estimates are inconsistent with the existence of powerful extragalactic synchrotron background associated with radio sources. Appreciable “quadrupole” anisotropy in is detected in the distribution of the spectral index of the synchrotron radiation of the Galaxy, and this anisotropy should be taken into account when estimating the polarization of the cosmic microwave background on small l. All the results are compared to the results obtained by foreign researchers in recent years.

The requirements toward the methods of “Clearing” the atmosphere in ground-based radio-astronomical observations of background emissions of the atmosphere

The results of a reduction of the dataset obtained with the RATAN-600 within the framework of the “Cosmological Gene” project are reported. The project was performed in order to estimate the contribution of atmospheric noise in observations of Galactic background radiation. Atmospheric noise prevails on time scales exceeded 10–100 seconds. The efficiency of preselecting the data with low atmospheric noise on the time scales of interest is demonstrated. The potential of the “Cosmological Gene” project for different accumulation times in the sky area studied are assessed with the effect of real atmospheric noise taken into account.

Galactic synchrotron emission according to the data of the RZF survey conducted at the RATAN-600 radio telescope

Deep 1–49 cm surveys of the circumzenithal sky area performed using the RATAN-600 radio telescope allowed the spectral index of Galactic synchrotron emission in the 7.6–49 cm wavelength interval to be refined. The data obtained are inconsistent with the model of synchrotron emission adopted to interpret the results of the first year of the WMAP mission, which led to the hypothesis of the early secondary ionization of the Universe at redshifts Z > 10–30. New observations made with the RATAN-600 demonstrated the possibility of deep studies of the intensity and polarization of the microwave background (the E component) in ground-based experiments at short centimeter wavelengths. Galactic synchrotron emission may as well limit the possibilities of space- and ground-based studies of the polarization of cosmic microwave background radiation arising as a result of scattering induced by relic gravitational waves (the B component). The sky area studied with the RATAN-600 is intended to be used to interpret the PLANCK mission data in order to ensure a more detailed account of the role of the Galactic synchrotron emission.

MARS-3 matrix radiometric system for RATAN-600

The MARS-3 third-generation matrix radiometric system has been developed, manufactured, and is currently being used in observations within the framework of the “Cosmological Gene” program. The system is based on new hardware components and consists of 16 independent radiometers (32 horns with a step of 20 mm). Each pair of horns is connected to the input of an amplifier unit via a square-loop modulator. The parameters of each radiometer are: central frequency, 30.0 GHz; bandwidth, 5GHz; average noise temperature of the system, 250 K; and a sensitivity of about 5 mK for τ = RC = 1 s.