The results of Waseda Radio Transient survey

Abstract

We report on several radio transients and a possibly long-term variable radio source detected by interferometric drift scan observation at Waseda Nasu Pulsar Observatory. Since May 2004, we have carried out the routine observations to search for radio transients and variable radio sources in our observable region, +32 deg<δ<+42 deg. In our observations, approximately 10 radio transients were detected by October 2006. Although these transients have still not been identified, we could find that these have mainly following three features. a) Most of transients were detected just once (only 1 transient was detected at the same position for two days). b) The distributions of radio transients could be isotropic in our observable region. c) These transients have a flux density on the order of Jy scale because the noise level of our system is approximately 300 mJy. To identify what type of objects these radio transients were, we have developed an alert system. If this alert system completes, we will obtain the positional information of detected radio transients within 70-min at a maximum from an appearance of the transients. By obtaining the positional information as soon as possible, we can carry out followup observations of these with other radio observatories.