GCN Circular 1386
Subject
GRB(XRF) 020427: X-ray afterglow with BeppoSAX
Date
2002-05-09T14:42:36Z (22 years ago)
From
Lorenzo Amati at TESRE/CNR <amati@tesre.bo.cnr.it>
L. Amati, Istituto di Astrofisica Spaziale e Fisica Cosmica, CNR,
Bologna; M. Capalbi, BeppoSAX Science Data Center, Rome; F. Frontera
University of Ferrara and Istituto di Astrofisica Spaziale e Fisica
Cosmica, CNR, Bologna; G. Gandolfi and L. Piro, Istituto di Astrofisica
Spaziale e Fisica Cosmica, CNR, Rome; J. J. M. in 't Zand, Astronomical
Institute, Uthrecht University; S. Granata and F. Reali, BeppoSAX Science
Operation Center, Rome, report: "The 3' error box of GRB(XRF) 020427
provided by the BeppoSAX Wide Field Cameras (GCN 1383) was observed with
the BeppoSAX MECS instrument (1.5-10 keV energy band) from Apr. 27.6220
(11.2 hr after the onset of the WFC event) to Apr. 27.7944 UT and from
Apr. 29.4439 to Apr. 29.6833 UT, for a total exposure time of 14878 s. A
previously unknown source lying inside the error box is detected at a 4.6
and 3.2 sigma level in the first and second observation, respectively, The
source, designated 1SAXJ2209.3-6519, is located at R.A. = 22h09m23s.2,
Decl. = -65o19'34.1" (equinox 2000.0; error radius 1'), which is 1'.1 from
the WFC-determined centroid. The average count rate during the first
observation is 0.0059 +/- 0.0013 count/s in the two MECS units,
corresponding to a 2-10-keV flux of (4.18 +/- 0.9) x 10**-13 erg cm**-2
s**-1, assuming a Crab-like spectrum. The average flux decreased by a
factor of about 2 during the second observation.
Due to its position and fading behavior, 1SAX J2209.3-6519 is likely the
X-ray afterglow of GRB(XRF) 020427. "
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