GCN Circular 2950
Subject
SGR 1806-20: RXTE/PCA pulse frequency during flare
Date
2005-01-14T18:00:12Z (21 years ago)
From
Peter Woods at UAH/MSFC <peter.woods@msfc.nasa.gov>
Pulse Frequency of SGR 1806-20 during the Giant Flare
P.M. Woods, M. Finger, S. Patel (USRA, NSSTC), C. Kouveliotou (NASA/MSFC,
NSSTC), Y. Rephaeli (UCSD), D. Gruber (Eureka), M. Persic (Obs.Ast.Trieste), R.
Rothschild (UCSD), D. Palmer, N. Gehrels, S. Barthelmy, E. Smith, J. Swank, and
C. Markwardt (GSFC) report:
We have re-analyzed the RXTE PCA data of the giant flare of 2004 December 27
from SGR 1806-20. We find that the pulse period reported in GCN #2927 of 7.579
+/- 0.002 s was strongly biased by pulse profile changes during the tail of
this flare. Excluding the first ~60 s of the flare where pulse profile changes
are strongest, we measure a barycenter-corrected pulse period of 7.5605 +/-
0.0006 s, significantly different than the previously reported measurement.