GCN Circular 375
Subject
GRB990704: SAX-NFI results summary
Date
1999-07-06T22:27:51Z (25 years ago)
From
Marco Feroci at IAS/CNR Frascati <feroci@ias.rm.cnr.it>
M. Feroci, G. Gandolfi, Istituto Astrofisica Spaziale, CNR, Roma,
L.A. Antonelli, Osservatorio Astronomico di Roma,
M.R. Daniele, BeppoSAX Science Data Center, Telespazio, Roma
C. De Libero, BeppoSAX Operation Control Center, Telespazio, Roma,
L. Di Ciolo and V. Torroni, BeppoSAX Science Operation Center,
Telespazio, Roma,
F. Frontera, Istituto Tecnologie e Studio Radiazioni Extraterrestri,
CNR, Bologna,
and J. Heise, Space Research Organization in the Netherlands, Utrecht,
on behalf of the BeppoSAX Team report:
The BeppoSAX Narrow Field Instruments observed the region of GRB990704
(GCN #366) from July 5.064 to July 5.989 UT. The observation was then
stopped to allow the follow-up observation of GRB990705.
One previously unknown X-ray source (1SAX J1219.5-0350) was found
inside the 7' BeppoSAX WFC error-circle (GCN #366) at a position (J2000)
R.A. = 12h19m27s.3 Decl.= -03o50'22", error radius 1' (90% confidence
level). The average source flux in 2-10 keV was (8.0+-0.6)x10E-3 counts/s,
corresponding to about 4.4x10E-13 erg cmE-2 sE-1, assuming a power
law spectrum.
The source shows a fading behaviour, strongly suggesting it is the
X-ray afterglow of GRB990704.