BATSE Discovery of Previously Unknown Soft Gamma-ray Repeater SGR1627-41
ATel #29; C. Kouveliotou, Universities Space Research Association, M. Kippen, P. Woods, G. Richardson, University of Alabama in Huntsville, V. Connaughton, National Research Council, report on behalf of the BATSE team at NASA/Marshall Space Flight Center
on 18 Jun 1998; 16:34 UT
Distributed as an Instant Email Notice Gamma-Ray Bursts
Credential Certification:
Subjects: Gamma Ray, Soft Gamma-ray Repeater
Referred to by ATel #: 30
BATSE has detected repeated soft gamma-ray bursts consistent with the
same (previously unknown) location. We recorded three bursts on June
15.109, 15.296, 15.411 UT (BATSE triggers 6825, 6826, 6827,
respectively) with an average duration of ~ 200 milliseconds.
Preliminary spectral analysis of the data indicates that the events
are very soft, with power law spectral indices varying between -3.0
and -7.0. BATSE triggered 5 more times, on June 17.873, 17.901,
18.004, 18.035, and 18.071 UT (BATSE trigger numbers 6833, 6834, 6835,
6836 and 6837, respectively). The last trigger had a peak count rate
of over 300000 counts/sec above background (integrated over 4
detectors between 20-1000 keV, in 1 second interval) and a duration of
~ 3 seconds. Due to its very high peak intensity, deadtime effects
prevent us from using it for localization, until we receive more data
types. The weighted location of the 7 remaining triggers is centered
on R.A. = 16h27m12.0s and dec = -41d06.0' with an error radius of
about 2 degrees. This location does not correspond to any previously
known SGR source; we conclude that we have discovered a new source,
SGR1627-41. We have initiated an RXTE ToO and we strongly encourage
wide field observations at other wavelengths.
