[ CATS home ] [ Back to CATS list ] [ ftp ]


The cosmological evolution of compact radio sources at 102 MHz

V.S. Artyukh, S.A. Tyul'bashev

A survey of compact ( q < 1") radio sources is being made with the Large Phased Array (LPA) of Lebedev Physical Institute. The observations are made with the interplanetary scintillations method at 102 MHz. It was investigated the one area of 7C survey centred at RA=6h28m and DEC=45d. The investigated square was 0.047 sr. There have been registered 125 sources with flux densities >0.15 Jy. The differential counts of the scintillating sources have been made. It was founded that the scintillating sources counts was close to sources counts in uniform Euclidean model up to S >0.7 Jy. There is very steep turnover of scintillating sources counts at S <0.7 Jy, it is steeper then one of 7C sources counts. This effect is caused by a different cosmology evolution of compact and extended radio sources.
1997AR...???..??? submitted! (received from authors)

The cosmological evolution of compact radio sources from 102 MHz observations.II

V.S. Artyukh, S.A. Tyul'bashev, E.A. Isaev


A survey of compact (theta < 1'') radio sources with interplanetary scintillation method was made at 102MHz with the Large Phased Array of the Lebedev Physical Institute. The survey covers the second area of the 7C survey, in direction RA = 10h28m and DEC = 41d, with area 0.097 ster. There were detected 289 scintillating sources.

The survey of scintillating radio sources in two areas of 7C survey has enabled to detect 414 compact sources, 380 of them 92% were detect first. The scintillating source count (from observations of two areas) has confirmed the decrease of the compact radio sources density for weak flux densities, which we found from observations of the first area. To flux density S = 0.5 Jy , the differential count of scintillating sources differs only little from that expected for a Euclidean Universe but a very sharp drop in the count curve is observed for weak flux densities S_102 < 0.5 Jy. This drop is significantly steeper than that for the 7C survey radio source count. This result confirms our early conclusion about different character of the cosmological evolution of compact and extended radio sources.

Both tables were formatted by S. Tyul'bashev and S.Trushkin