TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2444 SUBJECT: HETE Prompt GRB Spectral Analyses DATE: 03/11/13 02:49:01 GMT FROM: Roland Vanderspek at MIT HETE Prompt GRB Spectral Analyses The HETE team has enhanced its prompt burst analysis software to perform automatic spectral analyses of Fregate burst data and then immediately post the results to the HETE web site: http://space.mit.edu/HETE/Bursts This automatic spectral fit is derived from triggered data from the Fregate instrument for bursts which are localized by the WXM and/or the SXC. The process takes roughly five minutes to run, and it begins as soon as the full burst data set is received at MIT and the WXM localization has been confirmed: the results for a typical burst will be posted between 20 and 90 minutes after the burst, depending on the location of HETE in its orbit at the time of the trigger. At present, a cutoff power law is fit to the data, and the calculated values of Epeak, 25-100 keV fluence, and burst duration are posted, along with a plot of the spectral fit generated by XSPEC (to allow the observer the opportunity to check the automated results). Further details and caveats on the method are described at http://space.mit.edu/HETE/Bursts/Epeak_explanation.html The burst web page now also includes a histogram plot of the band C (30-400 keV) S/N ratio, which we have found to be an excellent means of identifying true XRFs. This process was first applied to GRB031026, and the results can be seen at http://space.mit.edu/HETE/Bursts/GRB031026 Further improvements in the prompt data to the web page are being implemented and will be announced as they are completed.