GRB 990123: An Extraordinary Example of an Ordinary Gamma-Ray Burst?

R.M. Kippen, M.S. Briggs, R.D. Preece

D.L. Band

C. Kouveliotou

J. van Paradijs

G.H. Share, R.J. Murphy

S.M. Matz

A. Connors

C. Winkler, O.R. Williams

M.L. McConnell, J.M. Ryan, C.A. Young

J.R. Catelli

B. Dingus

R.A.M.J. Wijers

Abstract

One of the most interesting gamma-ray burst discoveries in recent years was the simultaneous detection of GRB 990123 at optical, X-ray and gamma-ray wavelengths. Subsequent observations of this burst revealed optical, X-ray and radio afterglow counterparts, which eventually led to a redshift measurement, z 1.6. During the prompt emission phase, this burst was fortuitously observed by nearly all the instruments on the Compton Observatory, providing us with a detailed account of the gamma-ray emission properties. Although the burst was a large event in terms of its gamma-ray flux and fluence, its spectral properties are similar to the majority of the burst population. We will review the gamma-ray spectral and temporal properties of GRB 990123, concentrating on their relation to the full burst population and their relation to the prompt optical emission.


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On 16 Jul 1999, 09:19.