Broad-band spectra study of 213 VSOP 5-GHz survey sources

Citation
Ya. Kovalev et al., Broad-band spectra study of 213 VSOP 5-GHz survey sources, PUB AST S J, 52(6), 2000, pp. 1027-1036
Citations number
15
Categorie Soggetti
Space Sciences
Journal title
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
ISSN journal
00046264 → ACNP
Volume
52
Issue
6
Year of publication
2000
Pages
1027 - 1036
Database
ISI
SICI code
0004-6264(2000)52:6<1027:BSSO2V>2.0.ZU;2-L
Abstract
We present a statistical and model study of 1-22 GHz spectra and 5-GHz inte rpolated data for 213 of 230 sources with declinations delta > -30 degrees, selected for survey observations with the HALCA space radio telescope. The spectra of two subsamples were specially surveyed and monitored in 1997-20 00 as a ground spectra support for the space VLBI survey in the framework o f the VSOP Survey Programme. Every 1-22 GHz spectrum was measured with the RATAN-600 radio telescope at six wavelengths of 1.4, 2.7, 3.9, 7.7, 13, and 31 cm over a period of a few minutes (ten minutes or more near the pole). (25-30)% of the sources studied are outside of the VSOP selection criteria in 1997-2000 because of the variability of the VSOP sources, which were com piled from catalogs spanning a period between 1985 and 1996. About 60% of 1 86 VSOP/HALCA sources, monitored in 8 epochs, have amplitudes of variabilit y greater than +/-10% at 5 GHz over the three-year period. 45 new strong of 660 additionally surveyed sources have been found and can be added to the HALCA sample. 26 of 45 sources are new for the full VSOP list. Almost all V SOP sources are suggested to have continuous jets at milliarcsecond scales. This conclusion is supported by an analysis of the individual spectra for 213 objects, their mean statistical shape in the local frame, and the long- term variable spectra for 25 objects. Model and statistical analyses sugges t a common physical origin of the radio sources of various types in the stu died samples and in the majority of VSOP survey sources.