|
Description
The results of the very-low frequency (16.7MHz) survey of discrete sources made with the UTR-2 radio telescope is presented. The survey concerns the declination zones -13{deg} to -2{deg}, 0{deg} to 20{deg}, and 41{deg} to 60{deg}. The UTR-2 radio source catalogue contains an estimate of the coordinates and flux densities of 1819 sources measured at a number of the lowest frequencies used in contemporary radio astronomy within the range from 10 to 25 MHz. The catalogue is made of two parts: mean.dat: the averaged values of the coordinates and the corresponding errors, the source flux-density at the middle UTR-2 frequency 16.7 MHz as obtained from measured spectrum of the source at all UTR-2 frequencies and its error, the value of measured low-frequency spectral index with respect to which the estimate of has been obtained, the parameter W characterizing the integral reliability of the obtained source estimates and the corresponding object name from higher-frequency radio survey provided the source has been identified. To indicate the integral readability of the source parameters obtained we used the symbols A, B and C. These reliability estimates take into account the total number of measurements, coordinate scatter, number of frequencies and hour-angle settings at which the source parameters have been evaluated. The highly reliable observation results have been marked with symbol A . The sources whose parameters can be used without an additional analysis are marked with B and sources whose parameters are to be used with care have been marked with C. data.dat: this file contains the experimental estimates of the source coordinates and flux densities as well as their errors at each operating frequency of the UTR-2 in the order of their increasing; the total number (N) of successive observations according to which the estimates were obtained and the number of different hour-angle settings (NRA) of the reception pattern at which the source was observed. In cases when the observations did not allow us to obtain a reliable estimates of a source flux density the catalogue contains only their upper limits which are not accompanied by errors. The approximated values of as well as low-frequency spectral indices are presented only for those sources which have flux density estimates obtained at not less than three different UTR-2 frequencies.
|
