Radio Spectra of the RATAN-600 RZF objects and population analysis of weak radio sources Semenova T.A., Parijskij Yu.N., Bursov N.N. SAO RAS

We considered the next questions:  RZF (RATAN-600 Zenith Field) catalog  RZF and all-z luminosity range  Type of spectra of RZF catalog  RZF, FIRST and SDSS objects  Multi-band photometry

RZF and all-z Luminosity Range RZF High Radio Luminosity box VLA Deep Fields GB 5GHz Sky The modern luminosity function of radio sources of the surveys VLA deep fields, RATAN-600 and GB 5GHz. The RZF survey is intermediate, with is depth sufficient for the study of the whole part of the luminosity function connected with radio galaxies.

RZF (Ratan-600 Zenith Field) catalog The catalog is a part of the deep multi-frequency survey of the sky with RATAN-600 near the local zenith in a strip 0h <RA<24h, at DECLINATION =DEC 3C84 +/-2 arcmin. This catalog is resulted within the context of “Cosmological Gene” project (

Type of spectra Normal (-1.1<α ≤-0.5 ) 54.0% Flat (-0.5<α≤0) 25.8% Inverted (0<α ≤2.5 ) 6% Ultra Steep (-1.1 ≤ α <-2.0) 15.2%

Comparison of histograms of distribution of spectral indexes of strong radio sources (empty rectangles) and faint radio sources (filled rectangles, from data of the RZF catalog).

The histogram of a difference of distribution of spectral indexes of sources of surveys on RATAN-600 а) Strong (NCP> 200mJy) б) Weak (RZF survey <20mJy) The full number of objects was identical

RZF objects with inverted spectra  (~1% of RZF objects)

First attempt to estimate Spectra of the WEAKEST population of NVSS Sky From of NVSS objects we divided into types: MOST objects have NORMAL spectra USS population- 15% Inverted spectra- 5%

Identification of RZF objects of the FIRST catalog resulted in the following statistics  Empty fields 5%  Quasi-pointlike radio sources (LAS<6 arc sec)65% (LAS<6 arc sec)65%  Binary radio galaxies and quasars 13%  Triple objects 2%  Multiple objects 9%  Traces of “wind” in clusters 3%  Peculiar objects 3%

Sources Identifications Most of the sources were identified with NVSS and FIRST catalogs, but only 75% with SDSS. Analysis of morphology of objects at the mJy level led to the following conclusions:  The “point-like” population prevails (this is caused by too large red shifts Z for powerful radio galaxies and by transition to objects of small radio luminosity of the type AGN, Star-Burst galaxies). By “point-like” sources we mean objects that were not resolved by the catalog FIRST with its 6” diagram.  SDSS data often show sings of a possible gravitational disturbance of a host galaxy by a neighbor object.

Example of possible gravitational disturbances of a host galaxy by a neighbor object – the influence of close galaxies on generation of powerful radio emission

An example of a binary FRII type radio galaxy in the RZF survey band by data of the RZF, FIRST and SDSS catalogs

An example of an unusual object of the “FRII binary” type by data of the RZF, FIRST and SDSS catalogs

Multi-band photometry  About 20% of the RZF sources are beyond r=22.5 and should have z>1  Using the “Large Trio” experience, we found color red shifts for extremely faint SDSS objects.  Attempts of finding traces of “Break-galaxies” with the cut of optical emission beyond 912A by the SDSS filters u3540A, g4925A, r6335A, i7800A, z9294A gave a list of candidates to distant objects (Break-galaxies) z~ objects (g-r>2m) z~6 4 objects (r-i>2m) z~7 3 objects (i-r>2m) The getting of the powerful Ly-alpha line into a filter causes an increase of brightness in this filter over neighbor filters for the population of powerful galaxies which are strong emitters in the Ly-alpha line (the experiment of the “Large Trio” in RC J ). Analysis of obtained data resulted in detection of 3 analogous cases of the getting in the R filter (Z~4.2) and 3 cases in the I filter (Z~5.4).

Conclusions Most of the sources were identified with NVSS and FIRST catalogs, but only 75% with SDSS objects. Multi-band photometry of SDSS data showed that 20% of host galaxies are fainter than r=22.5m and they can have large red shifts (z>1). The population of FRII objects is presented worse in the RZF catalog than in catalogs with higher extreme fluxes. Observation confirmed a sharp fall of percentage of FRII objects. This does not contradict to recent models. This is usually interpreted as the change of a relative role of populations of objects with steep, flat and inverse spectra.

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λf0f0 ΔfΔfΔTΔTВходной усилительTaTсTс cmGHz Tph, KTtypeTn,KKK HEMT HEMT HEMT HEMT HEMT HEMT HEMT где λ и f 0 - длина волны и центральная частота, Δf - полоса частот, ΔT - чувствительность при постоянной времени 1 сек, Т ф и T ш - физическая и шумовая температуры входных усилителей и их типы: HEMT - транзистор с высокой подвижностью электронов, Т а * - температура антенны на средних углах возвышения, Т а ** - шумовая температура антенны в зените, Т с - общая шумовая температура системы.