GRANAT/SIGMA observation of GRB 920723 soft gamma-ray afterglow

R. A. Burenin; A. A. Vikhlinin; O. V. Terekhov; A. Yu. Tkachenko; S. Yu. Sazonov; M. R. Gilfanov; E. M. Churazov; R. A. Sunyaev; P. Goldoni; A. Claret; A. Goldwurm; J. Paul; J. P. Roques; E. Jourdain; G. Vedrenne; P. Mandrou

doi:10.1051/aas:1999295

All issues

Volume 138 / No 3 (September 1999)

Astron. Astrophys. Suppl. Ser., 138 3 (1999) 443-444

Abstract

Free Access

Issue		Astron. Astrophys. Suppl. Ser. Volume 138, Number 3, September 1999 Gamma-Ray Bursts in the Afterglow Era Contents Rome, November 3-6, 1998


Page(s)		443 - 444
DOI		https://doi.org/10.1051/aas:1999295
Published online		15 September 1999

Astron. Astrophys. Suppl. Ser. 138, 443-444 (1999)

GRANAT/SIGMA observation of GRB 920723 soft gamma-ray afterglow

R. A. Burenin¹, A. A. Vikhlinin¹, O. V. Terekhov¹, A. Yu. Tkachenko¹, S. Yu. Sazonov¹, M. R. Gilfanov¹^,2, E. M. Churazov¹^,2, R. A. Sunyaev¹^,2, P. Goldoni³, A. Claret³, A. Goldwurm³, J. Paul³, J. P. Roques⁴, E. Jourdain⁴, G. Vedrenne⁴ and P. Mandrou⁴

¹ 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

Received: 21 January 1999
Accepted: 16 April 1999

Abstract

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