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Gamma-ray burster recurrence timescalesThree optical transients have been found which are associated with gamma-ray bursters (GRBs). The deduced recurrence timescale for these optical transients (tau sub opt) will depend on the minimum brightness for which a flash would be detected. A detailed analysis using all available data of tau sub opt as a function of E(gamma)/E(opt) is given. For flashes similar to those found in the Harvard archives, the best estimate of tau sub opt is 0.74 years, with a 99% confidence interval from 0.23 years to 4.7 years. It is currently unclear whether the optical transients from GRBs also give rise to gamma-ray events. One way to test this association is to measure the recurrence timescale of gamma-ray events tau sub gamma. A total of 210 gamma-ray error boxes were examined and it was found that the number of observed overlaps is not significantly different from the number expected from chance coincidence. This observation can be used to place limits on tau sub gamma for an assumed luminosity function. It was found that tau sub gamma is approx. 10 yr if bursts are monoenergetic. However, if GRBs have a power law luminosity function with a wide dynamic range, then the limit is tau sub gamma 0.5 yr. Hence, the gamma-ray data do not require tau sub gamma and tau sub opt to be different.
Document ID
19850010633
Acquisition Source
Legacy CDMS
Document Type
Preprint (Draft being sent to journal)
Authors
Schaefer, B. E. (Maryland Univ. College Park, United States)
Cline, T. L. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
September 5, 2013
Publication Date
September 1, 1984
Subject Category
Space Radiation
Report/Patent Number
NAS 1.15:86157
NASA-TM-86157
Accession Number
85N18942
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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