The Spatial Coincidence of Two COMPTEL Gamma Ray Bursts: GRB930704 and GRB940301

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Session 15 -- Gamma Ray Bursts
Oral presentation, Monday, 30, 1994, 10:00-11:30

[15.02] The Spatial Coincidence of Two COMPTEL Gamma Ray Bursts: GRB930704 and GRB940301

J.M. Ryan, A. Connors, R.M. Kippen (UNH), V. Sch\"onfelder (MPE), W. Hermsen (SRON-Leiden), L. Hanlon, K. O'Flaherty (ESTEC), K. Hurley (UCB), B. McNamara, T. Harrison (NMSU), H. Pederson (Copenhagen U.)

We report on the spatial coincidence of two gamma ray bursts imaged by the COMPTEL experiment on the Compton Gamma Ray Observatory. These bursts, GRB930704 and GRB940301 out of a total of seventeen, are separated by $1.7\deg$ ($\sim$1 RMS $\sigma$ for these two bursts). They potentially arise from the same object, placing severe constraints on the cosmological origin of these events. Assuming gamma ray bursts are distributed isotropically and taking into account the COMPTEL sky exposure map, the probability of two random bursts occuring within $1.7\deg$ is less than 5\%. The lightcurves and spectra of the two bursts measured in both the telescope and spectroscopic modes differ significantly, ruling out the possibility that the two bursts are gravitationally lensed images of the same object. With the COMPTEL rate of burst detections within its field-of-view and assuming that this is a chance coincidence of independent events, another similar coincidence of bursts should not occur in another 50 years of COMPTEL operation.

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