Searches for simultaneous optical counterparts to gamma-ray bursts with GROCSE and ROTSE-I.

摘要

This work describes two experiments which searched for contemporaneous optical counterparts to gamma ray bursts (GRBs), GROCSE and ROTSE. The Gamma-Ray Optical Counterpart Search Experiment (GROCSE) used an automated rapidly slewing wide field of view optical telescope at Lawrence Livermore National Laboratory. The telescope was triggered in real time by the Burst And Transient Source Experiment (BATSE) data telemetry stream as processed and distributed by the BATSE COordinates DIstribution NEtwork (BACODINE), recently renamed the GRB Coordinates Network (GCN). GROCSE recorded sky images for 28 GRB triggers between January 1994 and June 1996. The analysis of the 12 best events is presented here, half of which were recorded during detectable gamma ray emission. No optical counterparts were detected to limiting magnitudes m _V ≤ 8.5 despite near complete coverage of burst error boxes.; The Robotic Optical Transient Search Experiment (ROTSE) continued this work with a faster, more sensitive, and more robust instrument, ROTSE-I. Prom the beginning of its run in March of 1998 through April 1999, ROTSE-I responded to 31 GRB triggers. On January 23, 1999 UTC, ROTSE-I detected the first-ever contemporaneous optical counterpart to a GRB, a bright transient with peak magnitude 8.86. The observations of this event and limits from four additional events are presented here.