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1980A&AS...42..227Kallas & Reich
1986AJ.....92..787Fich
1990AISAO..32..132Trushkin

These three principal papers:

A 21 cm radio continuum syrvey of the Galactic plane between l=93^o and l=162^o

E. Kallas & W. Reich

Summary

A 21 cm radio comtinuum survey of the galactic plane of an area between 93 < l <162^o and |b| < 4^o has been carried out with Effelsberg 100 m radio telescope. Contour maps are presented with a sensitivity in temperature of 0.2 K Tb and an angular resolution of 9' (HPBW). A list of 236 sources stronger than 0.3 Jy is given. The data have been calibrated in respect to the North Celestial Pole using scans obtained with the Stokert 25 m radio telescope at the same wavelength.

The temperature scale was determined by mapping the standard calibration sources 3C286 and 3C295 assuming 14.9 or 23.1 respectively. A conversion factor of 1 Jy ==1.5 K Ta for 53 % aperture effeciency was used.

In table II we have listed 236 radio sources found within the survyed area. EWe distinguish between unresolved point sources (P), slightly extended sources (EP), extended (E) with apparent diameters between 11' and 20', and very extended objects (VE). Radio structure with extents of more than 30' are not listed. The pak positions and peak flux density values are given. Integrated flux densities are given for sources where Gaussian fitting could be applied. Because the survey is slightly undersamlped we considered only sources with peak flux densities greater than 0.3 Jy. If available we listed flux densities from other catalogues selected from an updated version of the Master Source List of Radio sources (Dixon, 1970).


1986AJ.....92..787

A complee VLA survey in the outer Galaxy

Michel Fich

Abstract

The VLA has been used to make a "snapshot" survey of all radio continuum sources stronger than 0.3 Jy at 21 cm, smaller than 2 arcmin, and in the area in the area in the sky defined by l = 93^o to 163^o |b| < 4^o. These objects were observed at 6 cm with a resolution of 4 arcsec and sensitivity of 1 mJy. A second set of observations were carried out to determine the spectral indices of all objects not resolved in the 6 cm survey. These objects were observed at a wavelength of 2 cm with resolution and sensitivity similar to the 6 cm survey. The purpose of this study was to identify objects within the disk of the outer parts of our Galaxy. It is shown that the current lists of identified HII regions in this area are better than ~70 % complete for HII regions in the Perseum arm or closer. The only supernova remnants remaining to be discovered in this field are either extremely young, and therefore possibly radio quiet, or they are among those objects too extended to be observed at the VLA in this survey (i.e. greater that 2 arcmin in diameter).

The initial observing list comprised all of the objects not resolved (marked with a "P" for Point) in the KR catalog, a total of 135 objects. This designation implies that that the objects are smaller than 10', the size of their beam. All but one (KR70, missed because KR71 was mistakenly observed instead) of these objects were observed at the VLA in the C array configuration at a frequency of 4.885 GHz with a bandwidth of 50 MHz. Of the original 135 objects observed at 4.89 GHz, 81 of them (those not resolved at 4.89 GHz) were reobserved at the VLA in the D array configuration at a frequency of 14.96 GHz. The primary flux calibrator, 3C48, was assumed to have a flux density of 1.722Jy at 14.96 GHz. The incertainties in the spectral indices, as computed from the 10% uncertainly in each of the fluxes, are approximately 0.4 for each object. Most (60) of these 81 objects were not resolved (diameter less than 5 arcsec).

1990AISAO..32..132Trushkin

Investigation of the second Galactic quadrant radiosources from Kallas and Reich survey at 7.6 and 31.3 cm wavelength.

Trushkin S.A.

The RATAN-600 radio telescop has been used to investigate 61 from 71 unidentified extended sources and 11 compact sources with flat spectra from the survey made with Bonn 100 m radio telescope by Kallas and Reich in 1980 (KR-survey). These sources were abserved at 7.6 and 31.3 cm wavelength.

It is shown that 21 sources were not extended and they have the size, smaller than 1', the size of antenna beam at 7.6 cm. This sample of source has the mean spectral index a=-1.03, and they seem to be exragalactic. But one of them, KR95, possibly relates with a galactic pulsar, because of it has very steep spectrum a=-1.7 .

28 sources have shown two- (22) and three (6) component structure. Most of these sources seems to be extragalactic because of they have the compact non-thermal components. But nine double sources have one of component with thermal spectrum, and the components: KR15c, KR19a, KR21a, KR175a are weakextended ( < 3') sources. The compact component KR116b are identified with variable source GT0106+613 and has shown intersial specrtrum (a=0.54). Two compact components, KR43b, and KR166 have shown very steep nonthermal spectra (a < -1.5). KR58 is the compact planetary nebula NGC7354.

11 sources have wide extened structure, of size bigger 3'. Three of them: KR4, KR6 and KR140 have the flat spectra, and seem to be optical thin HII regions. Eight sources: KR48, KR74, KR114, KR171, KR180, KR184, KR191 and KR197, have nonthermal spectra. KR171, KR180 and KR191 have compact sources in extended structure. These eight sources can be unknown galactic supernova remnants (SNR). KR48 has spectral index a=-0.30 and can be a Crab-like SNR.

Eight from 11 compact sources seem to be HII regions. In some cases the the spectrum recieves in optical thin and optical thick regions of frequencies. There is a weak-extended component near the source KR70. Two sources: KR89 and KR143 have shown to have nonthermal spectra, and KR143 has shown extented structure. The spectra of all sources with more than three measurements of flux densities were plotted using all relevant catalogues.

The observations were carried out with Southern sector of RATAN-600 radio telescope in october 1988. Each source (SE, E) was observed 3-4 times at 7.6 and 31 cm wavelength. The flux calibration was made in observations of Cas A and Tycho (3C10) supernova remnants and quasar 3C147 and unindentified source 0403+76. The axcepted fux densities are in accodance with scale by Baars et al (1977).

Table 2
---------------------------------------
wl      Cas A   Tycho   3C147   0403+76
cm       Jy      Jy      Jy       Jy
---------------------------------------
 3.9    537     15.1     5.7      -
 7.6    895     23.1     9.9     3.25
31.0   2564     54.8    29.0     4.5