Search for Variable Sources Using Data of "Cold" Surveys

TL;DR

This study analyzes radio survey data from the RATAN-600 telescope spanning 1980-1994 to identify and characterize variable radio sources, revealing 41 potential variables with some confirmed by statistical criteria and optical data.

Contribution

It introduces a method to test for long-term variability in radio sources using historical survey data and provides a catalog of candidate variable sources with detailed analysis.

Findings

41 sources have positive long-term variability indices.

15 sources are reliably variable with high chi-square probabilities.

24 sources are variable or possibly variable in optical range.

Abstract

We search for variable sources, using the data of the surveys conducted on the RATAN-600 radio telescope in 1980-1994 at 3.94 GHz. To test the radio sources of the RCR (RATAN Cold Refined) catalog for variability, we estimated the long-term variability indices V of the studied objects, their relative variability amplitudes V_chi, and the chi-square probabilities p. Out of about two hundred considered sources, 41 proved to have positive long-term variability indices, suggesting that these sources may be variable. Fifteen objects can be considered to be reliably variable according to the chi-square criterion p > 0.98, three of these sources have chi-square probabilities p > 0.999. T he corresponding probabilities for six sources lie in the 0.95 < p < 0.98 interval, and those of the remaining 20 objects in the 0.73 < p < 0.95 interval. Twenty-four of 41 objects are variable or possibly variable in the optical range, and five objects are known variable radio sources. We construct the light curves and spectra for the sources with positive long-term variability indices.