Astron. Astrophys. Suppl. Ser.
Volume 138, Number 3, September 1999Gamma-Ray Bursts in the Afterglow Era Contents Rome, November 3-6, 1998
|Page(s)||443 - 444|
|Published online||15 September 1999|
GRANAT/SIGMA observation of GRB 920723 soft gamma-ray afterglow
Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117810 Moscow, Russia
2 Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85740 Garching bei Munchen, Germany
3 CEA, Centre d'Études de Saclay, France
4 Centre d'Étude Spatiale des Rayonnements, Toulouse, France
Accepted: 16 April 1999
We present GRANAT/SIGMA observations of the soft gamma-ray afterglow immediately after the bright GRB 920723. After s, the burst light curve makes a smooth transition into an afterglow where flux decays as t-0.7 for at least s. At least of main burst energy is emitted in the afterglow. The hardness of the afterglow spectrum corresponds to the power law spectral index , which is significantly softer than the main burst.
Key words: gamma-rays: bursts
© European Southern Observatory (ESO), 1999