THE CLOSELY POSITIONED THREE RADIO TRANSIENTS IN THE NASU 1.4 GHz WIDE-FIELD SURVEY

Abstract

In 2004, we started the Nasu 1.4 GHz wide-field survey to study the dynamic universe by simultaneously performing the surveillance of the wide-field sky. We have detected six radio transients with flux densities larger than 1 Jy. In this paper, we report the detection of three new radio transients in the drift-scanning observations at δ ∼ +417. Based on their positions in the sky and flux densities, we considered the candidate types of astronomical objects for transients. As a result, it is suggested that the three radio transients could be massive radio flares associated with known extragalactic sources, such as active galactic nuclei, which are usually very faint in X-ray and radio wavelengths. The three transients were found in the sky of 2° × 1°, while nine transients, including the three transients reported in this paper, are distributed at both high and low Galactic latitude. According to the observational results, we suggest that the wide-field survey simultaneously performed would be useful in searching for radio transients to study the dynamic radio sky.