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

Бурсов, Н. Н.; Pariiskii, Yu. N.; Maiorova, E. K.; Мингалиев, М. Г.; Berlin, Asher; Нижельский, Н. А.; Glushkova, I. A.; Семенова, Т. А.

doi:10.1134/s106377290703002x

Cited by 13 publications

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“…GPS and CSS sources are believed to account for 10% and 20% of the brightest representatives of active galactic nuclei (AGN), respectively. However, recent studies with the RATAN-600 have revealed that the corresponding fractions are much smaller [11][12][13][14][15]. The shape of the spectrum after turnover frequency is often explained in terms of the synchrotron self-absorption model (SSA -synchrotron self-absortion) or with the free-free absorption model (FFA -free-free absorption) [16].…”

Section: Introductionmentioning

confidence: 99%

Multifrequency Study of GHz-peaked Spectrum Sources

et al. 2019

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Gigahertz-Peaked spectrum (GPS) sources are compact active galactic nuclei, presumably young precursors of bright radio sources. The study of GPS radio properties provides information about the features of synchrotron radiation in extragalactic sources. Also in applied research GPS sources are useful as compact stationary radio sources in the sky for astrometric purposes. This paper presents the results of a multifrequency GPS study based on quasi-simultaneous measurements with the RATAN-600 radio telescope during the 2006-2017. The catalog containing spectral flux densities measured at six frequencies (1.1, 2.3, 4.8, 7.7/8.2, 11.2, and 21.7 GHz) have been obtained. In addition, for the analysis of radio spectra, data from the following low-frequency surveys have been used: GLEAM (GaLactic and Extragalactic All-sky Murchison widefield array survey) and TGSS (Tata institute for fundamental research GMRT Sky Survey) and high-frequency measurements from Planck survey. A total number of 164 GPS and candidates to GPS have been identified (17 of them are new discoveries), which makes up a small fraction of GPS in the initial sample of bright AGNs, about 2%. The physical properties and formation conditions of synchrotron radiation is found to be quite different in GPS of different AGN types. The deficit of distant GPS (z > 2) with low maximum frequencies (less than 1 GHz) is confirmed. The existing "size -peak frequency" anticorrelation is continuous. The continuum radio spectra are found to become statistically steeper with increasing redshift.

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Section: Introductionmentioning

confidence: 99%

Multifrequency Study of GHz-peaked Spectrum Sources

et al. 2019

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“…About 10 000 decimeter-wavelength radio sources fall in the region of the recently conducted survey carried out for the RATAN-600 Zenith Field (RZF; at the declination of 3C 84 δ 2000 = 41 • 30 42 , 360 • × 2 • × cos δ in size) [10,11]. Their positions, coincident with the positions of objects from the FIRST catalog, are given in Fig.…”

Section: Noise Due To Background Extragalactic Radio Sourcesmentioning

confidence: 98%

Statistical radio astronomy of the 21st century

et al. 2015

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The exponential development of radio-astronomy methods (sensitivity, resolution, depth of surveys, etc) has led to the need for new methods aimed at distinguishing weak signals in the midst of numerous background signals, as has long been the case for radio astronomy at meter wavelengths. Centimeter-wavelength data accumulated with existing radio telescopes (such as the RATAN-600 reflector-the largest radio telescope in Russia) are presented, and expected problems for major new radio telescopes of the 21st century, such as the Square Kilometer Array, are discussed. The effectiveness of using certain tested methods to derive astrophysically important results through reasonable statistical processing of large datasets is shown. In experiments conducted with RATAN-600, these methods lead to an enhancement in sensitivity by an order of magnitude compared with the sensitivity of a resolving element.

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“…There remains noise due to weak background sources at the sub-mJy level at 7.6 cm, which is fairly firmly detected statistically (via the cross correlation of independent data sets) in deep surveys such as KHOLOD (see also the circum-zenith survey described in [45,46]). These sources are not detected in the NVSS catalog at 21 cm.…”

Section: Noise Due To Background Sourcesmentioning

confidence: 98%

The KHOLOD experiment: A search for a new population of radio sources

et al. 2012

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Published data from long-term observations of a strip of sky at declination δ ≈ 5 • carried out at 7.6 cm on the RATAN-600 radio telescope are used to estimate some statistical properties of radio sources. Limits on the sensitivity of the survey due to noise imposed by background sources, which dominates the radiometer sensitivity, are refined. The vast majority of noise due to background sources is associated with known radio sources (for example, from the NVSS with a detection threshold of 2.3 mJy) with normal steep spectra (α = 0.7-0.8, S ∝ ν −α ), which have also been detected in new deep surveys at decimeter wavelengths. When all such objects are removed from the observational data, this leaves another noise component that is observed to be roughly identical in independent groups of observations. We suggest this represents a new population of radio sources that are not present in known catalogs at the 0.6 mJy level at 7.6 cm. The studied redshift dependence of the number of steep-spectrum objects shows that the sensitivity of our survey is sufficient to detect powerful FRII radio sources at any redshift, right to the epoch of formation of the first galaxies. The inferred new population is most likely associated with low-luminosity objects at redshifts z < 1. In spite of the appearance of new means of carrying out direct studies of distant galaxies, searches for objects with very high redshifts among steep and ultra-steep spectrum radio sources remains an effective method for studying the early Universe.

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

Cited by 13 publications

References 0 publications

Multifrequency Study of GHz-peaked Spectrum Sources

Multifrequency Study of GHz-peaked Spectrum Sources

Statistical radio astronomy of the 21st century

The KHOLOD experiment: A search for a new population of radio sources

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