A Search for Untriggered GRB Afterglows with ROTSE-III
Abstract
We present the results of a search for untriggered gamma-ray burst (GRB) afterglows with the Robotic Optical Transient Search Experiment-III (ROTSE-III) telescope array. This search covers observations from September 2003 to March 2005. We have an effective coverage of 1.74 deg^2 yr for rapidly fading transients that remain brighter than ~ 17.5 magnitude for more than 30 minutes. This search is the first large area survey to be able to detect typical untriggered GRB afterglows. Our background rate is very low and purely astrophysical. We have found 4 previously unknown cataclysmic variables (CVs) and 1 new flare star. We have not detected any candidate afterglow events or other unidentified transients. We can place an upper limit on the rate of fading optical transients with quiescent counterparts dimmer than ~ 20th magnitude at a rate of less than 1.9 deg^-2 yr-1 with 95% confidence. This places limits on the optical characteristics of off-axis (orphan) GRB afterglows. As a byproduct of this search, we have an effective ~ 52 deg^2 yr of coverage for very slowly decaying transients, such as CVs. This implies an overall rate of outbursts from high galactic latitude CVs of 0.1 deg^2 yr^-1.
Cite
@article{arxiv.astro-ph/0506442,
title = {A Search for Untriggered GRB Afterglows with ROTSE-III},
author = {E. S. Rykoff and F. Aharonian and C. W. Akerlof and K. Alatalo and M. C. B. Ashley and T. Guver and D. Horns and R. L. Kehoe and U. Kiziloglu and T. A. McKay and M. Ozel and A. Phillips and R. M. Quimby and B. E. Schaefer and D. A. Smith and H. F. Swan and W. T. Vestrand and J. C. Wheeler and J. Wren and S. A. Yost},
journal= {arXiv preprint arXiv:astro-ph/0506442},
year = {2009}
}
Comments
Seven pages, five figures, uses emulateapj class file. Accepted to Astrophysical Journal