Simultaneous spectra and radio properties of BL Lac's

We present the results of nine years of the blazar observing programme at the RATAN-600 radio telescope (2005-2014). The data were obtained at six frequency bands (1.1, 2.3, 4.8, 7.7, 11.2, 21.7 GHz) for 290 blazars, mostly BL Lacs. In addition, we used data at 37 GHz obtained quasi-simultaneously with the Metsahovi radio observatory for some sources. The sample includes blazars of three types: high-synchrotron peaked (HSP), low-synchrotron peaked (LSP), and intermediate-synchrotron peaked (ISP). We present several epochs of flux density measurements, simultaneous radio spectra, spectral indices and properties of their variability. The analysis of the radio properties of different classes of blazars showed that LSP and HSP BL Lac blazars are quite different objects on average. LSPs have higher flux densities, flatter spectra and their variability increases as higher frequencies are considered. On the other hand, HSPs are very faint in radio domain, tend to have steep low frequency spectra, and they are less variable than LSPs at all frequencies. Another result is spectral flattening above 7.7 GHz detected in HSPs, while an average LSP spectrum typically remains flat at both the low and high frequency ranges we considered.Comment: 14 pages, 6 figures. Accepted for publication in Astronomische Nachrichte

RATAN-600 multi-frequency data for the BL Lacertae objects

We present a new catalogue of the RATAN-600 multi-frequency measurements for BL Lac objects. The purpose of this catalogue is to compile the BL Lac multi-frequency data that is acquired with the RATAN-600 simultaneously at several frequencies. The BL Lac objects emit a strongly variable and polarized non-thermal radiation across the entire electromagnetic spectrum from radio to gamma rays and represent about 1% of known AGNs. They belong to the blazar population and differ from other blazars&#39; featureless optical spectrum, which sometimes have absorption lines, or have weak and narrow emission lines. One of the most effective ways of studying the physics of BL Lacs is the use of simultaneous multi-frequency data. The multi-frequency broadband radio spectrum was obtained simultaneously with an accuracy of up to 1-2 min for four to six frequencies: 1.1, 2.3, 4.8, 7.7, 11.2, and 21.7 GHz. The catalogue is based on the RATAN-600 observations and on the data from: equatorial coordinate and redshift, R-band magnitude, synchrotron peak frequency, SED classes, and object type literature. The present version of the catalogue contains RATAN-600 flux densities measurements over nine years (2006-2014), radio spectra at different epochs, and their parameters of the catalogue for more than 300 BL Lacs objects and candidates. The BL Lacs list is constantly updated with new observational data of RATAN-600.</p

Assessing economic losses of lake Kaban (Kazan, RUSSIA) ecosystem and developing of compensation measures within the framework of sports facilities construction

© MCSER-Mediterranean Center of Social and Educational Research. We have calculated the environmental losses arising in the course of preparation and construction activities on the lake Kaban. The size of environmental damage caused under construction was evaluated in a total of $ 273,863 USA. Developed compensatory measures that reduce the effects of damage caused by the construction work. We have developed a concept of biological rehabilitation of the lake and we have made prediction of change in the state of the lake ecosystem as a result of rehabilitation measures

Assessing economic losses of the small river ecosystems and developing of compensation measures within the framework of sports facilities construction

The article describes the basic theoretical principles that underpin the economic calculation of environmental damage in the course of human economic activity. As an example the assessing of the losses from the impact of the construction of sports facilities in the floodplain of a small river. We have calculated the environmental losses arising in the course of preparation and construction activities. Developed compensatory measures that reduce the effects of damage caused by the construction work

Observations of the bright radio sources in the North Celestial Pole region at the RATAN-600 radio telescope

A survey of the North Celestial Pole region using the RATAN-600 radio telescope at five frequencies in the range 2.3 to 21.7 GHz is described. Sources were chosen from the NVSS catalogue. The flux densities of 171 sources in the Declination range +75 to +88 are presented; typical flux density errors are 5-10 percent including calibration errors. About 20 percent of the sources have flat spectra or a flat component.Comment: 21 pages, 7 figures; to be published in Astronomy and Astrophysics (without last figure with the spectra of the observed sources

The RATAN-600 multi-frequency catalogue of blazars -- BLcat

In this paper we present the RATAN-600 multi-frequency catalogue of blazars, an updated version of the BLcat: the RATAN-600 multi-frequency catalogue of BL Lacertae objects. The main novelty in the catalogue is an extension of the sample with flat-spectrum radio quasars (FSRQs), thus currently it contains more than 1700 blazars of different types. The main feature of the BLcat is a compilation of radio continuum data for blazars based on the RATAN-600 quasi-simultaneous measurements at frequencies of 1.1, 2.3, 4.7, 7.7/8.2, 11.2, and 21.7/22.3 GHz. We additionally supplement the catalogue with the radio data from external sources to provide an opportunity to more complete study of radio spectra and radio light curves. For the convenience of users, we developed tools to calculate the spectral index, variability index, and radio luminosity. We briefly describe basic radio properties of blazar subsamples of the catalogue: spectral classification, spectral indices, flux density variability, and radio luminosity.Comment: 9 pages, 8 figure

Radio properties of high-redshift galaxies at z≥1z \geq 1

Study of high-redshift radio galaxies (HzRGs) can shed light on the active galactic nuclei (AGNs) evolution in massive elliptical galaxies. The vast majority of observed high-redshift AGNs are quasars, and there are very few radio galaxies at redshifts $z>3$. We present the radio properties of 173 sources optically identified with radio galaxies at $z\geqslant1$ with flux densities $S_{1.4}\geqslant20$ mJy. Literature data were collected for compilation of broadband radio spectra, estimation of radio variability, radio luminosity, and radio loudness. Almost 60% of the galaxies have steep or ultra-steep radio spectra; 22% have flat, inverted, upturn, and complex spectral shapes, and 18% have peaked spectra (PS). The majority of the PS sources in the sample (20/31) are megahertz-peaked spectrum sources candidates, i.e. possibly very young and compact radio galaxies. The median values of the variability indices at 11 and 5 GHz are $V_{S_{11}}=0.14$ and $V_{S_{5}}=0.13$, which generally indicates a weak or moderate character of the long-term variability of the studied galaxies. The typical radio luminosity and radio loudness are $L_{5}=10^{43}$ - $10^{44}$ erg*s$^{-1}$ and $\log R=3$ - $4$ respectively. We have found less prominent features of the bright compact radio cores for our sample compared to high-redshift quasars at $z\geq3$. The variety of the obtained radio properties shows the different conditions for the formation of radio emission sources in galaxies

A study of the synchrotron component in the blazar spectral energy distributions

© Pleiades Publishing, Ltd., 2015. We study the synchrotron component of nonthermal radiation of blazars using the spectral energy distribution (SED). The sample contains a total of 877 blazars, including 423 flat-spectrum radio quasars (FSRQs), 361 BL Lac objects and candidates, and 93 blazars of uncertain type. Using the ASDC SED Builder Tool, we have made an estimation of the synchrotron peak frequency νspeak using archive data of different catalogs. The position of the synchrotron peak frequency was determined for 875 objects, which were further classified as follows: 611 low-synchrotron peaked (LSP) blazars (νspeak 14.5 Hz), 222 intermediate-synchrotron peaked (ISP) blazars (1014.5 s peak speak > 1016.5 Hz). For the FSRQs the average νspeak is 1013.4±1.0 Hz, for the BL Lac-type blazars it equals 1014.6±1.4 Hz. We found that νs peak values and the spectral flux density at 4.8 GHz form different distributions for two types of blazars—FSRQ and BL Lac— and for the radio-selected (RBLs) and x-ray-selected (XBLs) blazars. The distribution of νspeak values is broader for BL Lac objects than for FSRQs. There are no ultra-high-energy synchrotron-peak BL Lac objects (UHBLs, with νspeak > 1019 Hz) in our sample. We have found very-low-synchrotron peaked (VLSP) blazar candidates (with νspeak < 1013 Hz). Most of them are the FSRQs (41% of the total number) and only 9%are the BL Lac objects. Our results confirm the results of other authors, made on the samples with a significantly smaller number of objects