TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2604 SUBJECT: Activivty of SGR 1806-20 DATE: 04/05/28 13:46:43 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks on behalf of Konus-Wind and Helicon/Coronas-F teams, T. Cline on behalf of the Konus-Wind team, and A. Rau, A. von Kienlin, G. Lichti on behalf of the INTEGRAL SPI-ACS GRB team report: Recently, Konus-Wind has detected seven SGR-like bursts in the trigger mode: Date Time, Duration, Fluence, Peak Flux, kT**** s UT s (20-200 keV) (20-200 keV) keV ergs/cm2 ergs/cm2 s ----------------------------------------------------------------------- 040427 47089.452 0.176 (3.43 +/- 0.07)E-6 (2.58 +/- 0.22)E-5 19+/-3 040519* 72250.485 1.376 (2.74 +/- 0.02)E-5 (3.19 +/- 0.09)E-5 21+/-2 040522** 31696.702 0.176 (2.16 +/- 0.06)E-6 (2.82 +/- 0.17)E-5 16+/-5 040522 45772.875 0.136 (1.33 +/- 0.04)E-6 (1.59 +/- 0.12)E-5 25+/-6 040523 50502.964 0.552 (4.32 +/- 0.09)E-6 (2.94 +/- 0.14)E-5 16+/-5 040525*** 12976.933 0.592 (8.74 +/- 0.12)E-6 (3.06 +/- 0.11)E-5 23+/-4 040526 29173.030 0.752 (5.88 +/- 0.11)E-6 (1.41 +/- 0.09)E-5 16+/-5 ------------------------------------------------------------------------ * - this burst was localized, the most like source of the burst is SGR 1806-20 (GCN 2603). ** - this burst was also detected by Helicon-Coronas-F in the background mode. Estimated time delay is consistent with SGR 1806-20 position. *** - this burst was also detected by INTEGRAL SPI-ACS. We have triangulated it to an annulus centered at RA(2000) = 259.389 deg, Decl(2000) = -17.958 deg, whose radius is 12.616 +/- 1.770 deg (3 sigma). The center line of this annulus passes 0.4 degrees from the position of SGR 1806-20. **** - the last column contains the values of spectral parameter kT for the OTTB spectral model: dN/dE ~ E^{-1} exp(-E/kT) Additionally, a number of SGR-like bursts (short and soft) were detected by both Konus detectors S1 and S2 in the background mode: Date Time, s UT (hh:mm:ss) --------------------------- 040519 25976 (07:12:56) 040519 86378 (23:59:38) 040520 44823 (12:27:03) 040522 2693 (00:44:53) 040522 30582 (08:29:42) 040522 80762 (22:26:02) 040522 83738 (23:15:38) 040523 18673 (05:11:13) 040523 39091 (10:51:31) 040523 40937 (11:22:17) 040523 65789 (18:16:29) The Konus ecliptic latitude response indicates that the source of the bursts is near ecliptic plane. All these data lead to the supposal that the all these bursts originated from SGR 1806-20, which, hereby, has entered a new phase of activity in the hard X-ray.