The Ratan Galactic Plane Survey

Abstract

Now in radio continuum surveys more than 10,000 radio sources have discovered in the Milky Way plane but the Galactic origin only of a small part of them has been determined. The problem comes from the absence of estimates of source distance and the optical identification even for bright radio sources, and the most of sources have not spectral data at 2-3 frequencies. As followed some hundreds of sources have not classified as thermal or non-thermal. Now we don't know the full number of supernova remnants (SNRs) in the Galaxy. The simple estimates show that a sample of Galactic SNRs is not full as for weak and extended (> 15′) as for bright and compact (< 3′) SNRs (Trushkin 1993).

Radio Spectra of Complete Sample of Galactic Supernova Remnants

“…We used our measurements of the flux densities of about 120 SNRs (Trushkin, 1986(Trushkin, , 1996a(Trushkin, ,b, 1997Trushkin et al, 1988). We added to the list of SNRs four first detected SNRs: G3.2−5.2, G11.2−1.1, G16.0+2.7 and G356.2+4.4, and also the SNR candidates G4.7+1.3, G4.8+1.2, G4.8+6.2, G9.7−0.1 and G85.2−1.2 from Duncan et al (1997) and Taylor et al (1992).…”

“…We used our measurements of the flux densities of nearly 120 SNRs (Trushkin, 1986;Trushkin et al, 1988;Trushkin, 1996aTrushkin, ,b, 1997. Thus the flux densities of half of the SNRs were measured at several (up to six) frequencies, which corrected and complemented essentially the spectra of many SNRs.…”

“…Spectrum plotting is an "on-line" procedure of the CATS database (Verkhodanov et al, 1997) created for some other multi-frequency catalogs. These spectra include most of the measurements available in literature, as well as multi-frequency measurements of nearly 120 SNRs with the RATAN-600 radio telescope in 1, 2 and 4 Galactic quadrants and from the Galactic plane survey at 960 and 3900 MHz (Trushkin, 1986(Trushkin, , 1988(Trushkin, , 1989(Trushkin, , 1996(Trushkin, , 1998. The measurements have been placed on the same absolute flux density scale of Baars (1977) as in the paper by Kassim (1989a), using the correcting factor from the compiled catalog (Kuhr et al, 1981).…”

The Radio Spectral Index of the Crab Nebula

“…Thirdly, several groups have reported a steepening of the spectral index near the edge of the nebula. (Velusamy & Sarma 1977, Agafonov 1987 These measurements, however, are difficult to make, and other groups report no steepening of α towards the edges of the nebula (Wilson 1972, Swinbank 1980, Trushkin 1986. If such a steepening is real, then it could be interpreted as evidence for a shell of emission around the Crab, analogous to the steeper spectrum shell-type emission typically observed from classical shell-type SNRs (e.g.…”

Study of Objects of Low Radio Frequency Catalogues and IRAS Data — Cross-Identification

“…In the future we propose to study them with the RATAN-600 radio telescope. Part of these sources in the Galactic plane could be identified with sources from the new Galactic survey, carried out by Trushkin (1995).…”