Skip to main content
New Swift-BAT/GUANO and IceCube Notice Types Available! See news and announcements

GCN Circular 5208

Subject
GRB 060602B: Swift-BAT Refined Analysis
Date
2006-06-04T00:00:01Z (18 years ago)
From
Hans Krimm at NASA-GSFC <krimm@milkyway.gsfc.nasa.gov>
D. Palmer (LANL),  L. Barbier (GSFC),  S. Barthelmy (GSFC),
J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC),
D. Hullinger (BYU-Idaho), M. Koss (GSFC/UMD), H. Krimm (GSFC/USRA),
C. Markwardt (GSFC/UMD), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU),
G. Sato (GSFC/JSPS/USRA), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),
on behalf of the Swift-BAT team:

Using the data set from T-119.1 to T+182.9 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 060602B
(trigger #213190)  (Schady, et al., GCN 5200).  The BAT 
ground-calculated position
is (RA,Dec) = 267.368, -28.121 deg {17h 49m 28.2s, -28d 7' 15.5"} (J2000)
+- 1.4 arcmin, (radius, sys+stat, 90% containment).  The partial 
coding was 100%.

The light curve shows a single boxcar shaped peak from ~T-1.0 to ~T+12.0 sec.
The peak is strongest in the 15-25 keV band and is not seen above 50 keV.
T90 (15-350 keV) is 9.0 +- 2 sec (estimated error including systematics).

The time-averaged spectrum from T-1.1 to T+8.8 is best fit by
a simple power-law model.   The power law index of the time-averaged
spectrum is 5.02 +- 0.52. The fluence in the 15-150 keV band is
1.8 +- 0.2 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from
T+5.94 sec in the 15-150 keV band is 0.8 +- 0.1 ph/cm2/sec.  All the quoted
errors are at the 90% confidence level.

We note that this is one of the softest spectra yet seen in the BAT for a GRB.
The spectra plus the galactic coordinates of the source:  galactic lon, lat:
1.15, -0.30 deg suggest that this source may be an X-ray burster rather than
a classical GRB.  Analysis of XRT and other ground and satellite based
observations will help to settle this question.  Therefore further observations
are encouraged.
Looking for U.S. government information and services? Visit USA.gov