|HETE Burst H2275|
Burst H2275 summary
Download ASCII table of Fregate Band A, B, C lightcurves here.
An automated fit of a cutoff power-law spectrum has been performed for H2275. The fit of the model to the data is shown below; the calculated values of Epeak and the burst fluence (30-400 keV) are:
Epeak = 116.47 keV Fluence = 1.188e-05 erg/cm^2 Duration = 23.200 seconds
These results are computed by an automatic script. Please visually inspect the XSPEC summary plot to judge the quality of the results.
Please note that this value of Epeak results from a fit to FREGATE data (8-400 keV) only -- a more reliable joint fit to FREGATE and WXM data is not yet automated. As such, this Epeak estimate is likely to be biased high, especially for soft events, such as XRFs. In our experience, the inclusion of WXM data can lower the value of E_peak substantially. The above Epeak value should thus be viewed as a preliminary estimate.
Click here for an explanation of the method.
TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1508 SUBJECT: GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC DATE: 02/08/19 22:50:50 GMT FROM: George Ricker at MIT
GRB020819(=H2275): A Long Burst Localized by the HETE WXM and SXC R. Vanderspek, J. Villasenor, J.G. Jernigan, G. Monnelly, J. Doty, G. Crew, N. Butler, T. Cline, A. Levine, F. Martel, E. Morgan, G. Prigozhin, G. Azzibrouck, J. Braga, R. Manchanda, and G. Pizzichini, on behalf of the HETE Optical-SXC and HETE Operations Teams; G. Ricker, J-L Atteia, N. Kawai, D. Lamb, and S. Woosley on behalf of the HETE Science Team; Y. Shirasaki, C. Graziani, M. Matsuoka, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Tavenner, and T. Donaghy, on behalf of the HETE WXM Team; M. Boer, J-F Olive, J-P Dezalay, and K. Hurley on behalf of the HETE FREGATE Team; write: At 14:57:35.82 UTC (53855.82 s UT) on 19 Aug 2002, the HETE FREGATE, WXM, and SXC instruments detected event H2275, a moderately bright, long GRB. In the FREGATE 8-40 keV band, the burst had a duration of ~20 seconds, and a peak brightness of ~5x Crab. A GCN Burst Alert Notice was disseminated 55s after the burst. No real-time optical camera aspect was generated at the time of the burst; thus, no WXM real-time localization could be disseminated. Ground analysis of the optical camera data, and of the WXM data for the burst, produced a refined location which was reported in a GCN Position Notice issued 98 minutes after the burst. The WXM location can be expressed as a 90% confidence circle that is 7 arcminutes in radius and is centered at WXM: RA = 23h 27m 07s, Dec = +6o 21' 50" (J2000). Ground analysis of the SXC data for the burst also produced a refined location, which was reported in a GCN Position Notice issued 176 minutes after the burst. The SXC location can be expressed as a 90% confidence circle that is 130 arcseconds in radius and is centered at SXC: RA = 23h 27m 24s, Dec = +6o 16' 08" (J2000). We note that the SXC error circle (reported at 17:54:08 UTC) lies almost fully within the subsequently-reported IPN annulus (Hurley et al, GCN1507, issued at 19:30:40 UTC). Also, the catalogued X-ray source 1RXS J232705.9+062419 lies within the WXM error box, but is not within the SXC error box. Further information (including a light curve and the error boxes) for GRB020819 is provided at the following URL: http://space.mit.edu/HETE/Bursts/ This message is citable.
The sky map for GRB020819 (H2275). Shown are the error circles from the WXM, the SXC, and the annulus calculated by the IPN using HETE and Ulysses data. To date (0h UT 2002 August 20), no counterpart to GRB020819 has been found.