IAUC on RXTE Detection of the Afterglow from GRB 970616
Issued by CBAT: Thu, 19 Jun 1997 17:28:57 -0400
Circular No. 6683
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
BMARSDEN@CFA.HARVARD.EDU or DGREEN@CFA.HARVARD.EDU (science)
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V. Connaughton, National Academy of Sciences/National Research Council and Marshall Space Flight Center (MSFC);
R. M. Kippen, R. Preece, and G. N. Pendleton, University of Alabama at Huntsville and MSFC;
and S. D. Barthelmy, Universities Space Research Association (USRA) and Goddard Space Flight Center (GSFC), report for the BATSE team:
"The transient x-ray XTE source reported below by Marshall et al. lies in the error box of a gamma-ray burst seen by BATSE on June 16.757 UT.
The Rapid Burst Reponse location, which was distributed through the GRB Coordinates Network/BATSE Coordinates Distribution Network, 20 min after the initial trigger, was R.A. = 1h21m51s, Decl. = -7 09'.4 (equinox 2000.0), with a 1-sigma error radius of 0.3-degree statistical and about 2 deg systematic.
The burst was multipeaked, with a total duration of about 200 s.
A maximum flux of 23.8 +/- 0.5 photons cmE-2 sE-1 (above 20 keV) was measured 90 s after the trigger time, placing this event in the brightest 2 percent of all BATSE bursts.
Its total fluence above 20 keV is estimated to be 4.01 +/- 0.14 x 10E-5 erg cmE-2."
F. E. Marshall, GSFC;
T. Takeshima, and S. D. Barthelmy, USRA and GSFC;
C. R. Robinson, USRA and MSFC; and K. Hurley, University of California at Berkeley, report
the detection of an x-ray afterglow for the gamma-ray burst detected with BATSE on June 16.7568 UT.
Scanning observations with the Proportional Counter Array on the Rossi X-ray Timing Explorer (RXTE) 4.0 hr after the burst revealed a source at R.A. = 1h18m.9 +/- 0m.7 (90-percent statistical confidence), Decl. = -5 30' +/- 18' (equinox 2000.0) with a countrate of 4.5 +/- 1.6 counts/s or 1.1 x 10E-11 erg sE-1 cmE-2 in the band 2-10 keV.
It is the brightest source detected within the 2-deg BATSE error circle, and it also overlaps the preliminary inter-planetary network (IPN) annulus determined from the time difference in the BATSE and Ulysses detections.
The IPN annulus has a radius of 49.808 deg, is centered at R.A. =22h10m30s, Decl. = -27o24'.8, and has a full width of 4'.6.
An annulus with a smaller width will be available after further processing.
The intersection of the error regions has corners at 1h19m.6, -5 49'; 1h19m.6, -5 40'; 1h18m.4, -5 12'; 1h18m.2, -5 16'.
A subsequent RXTE observation on June 18.08 detected no significant flux from this position, with a preliminary 90-percent confidence upper limit of 2.5 counts/s.
With the kind permission of Dr Brian Marsden of the International Astronomical Union's Central Bureau for Astronomical Telegrams, the full text of IAU circulars concerning RXTE is reprinted here - a week after their original promulgation by the IAU.
Please note that the text above includes only the parts of the IAUC relevant to RXTE, and that some IAUC contain more than one bulletin about RXTE.
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