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S. A. Scoles (Agnes Scott College), G. I. Langston (NRAO)
Transient radio sources are markers of unique phenomena and important probes of fundamental physics. We discuss the currently available limits on the number of radio bright transient events and describe a plan for detection of transient radio sources using Very Large Array archive data. The data analysis plan for transient source detection is tested by examination of two epochs of observation of galaxy M81.
We present a study of two epochs of observations of galaxy M81 to find transient radio sources brighter than 10 mJy and 10 sigma occurring on time scales of 30 s to 30 m and 10 to 15 years. Candidate transients are proposed and analyzed.
A comparison is made by generating a map of each data set and finding the coordinates and peak flux of each source in the field. By coincidence, one transient, SN1993J, is re-detected using this method.
To search for short-term transients, we use VLA observations to generate a graph of the average flux over a series of 30 s time intervals. One candidate short term event was found using this method and confirmed in the appropriate images when the data sets were individually subtracted from an average flux image. This short-term transient, however, is more probably explained by local interference than by an astronomical phenomena.
The detection of two candidate transients in a small angular area of the sky is unexpected as previous upper limits of transient density are much lower.
If you would like more information about this abstract, please follow the link to http://www.gb.nrao.edu/$\sim$glangsto/m81. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.
The author(s) of this abstract have provided an email address for comments about the abstract: glangsto@nrao.edu
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.