TO: All GCN Notice recipients RE: IPN_RAW Notice type is available DT: 02 Sep 08 INTRODUCTION: A new notice type has been added to the GCN system. It is called the IPN_RAW type. This type comes in two subtypes: (a) a Timestamp-only version which contains just a timestamp of when one of the various IPN-contributing missions triggers on an event or discovers a significant rate increase in their countrate data, and (b) an Annulus version which contains the results of a 2-mission detection yielding an annulus on the sky. (Note that the IPN_POS Notice already exists to handle the 3-or-more-mission 'single' and 'double' error boxes scenarios.) Further information can be found at http://gcn.gsfc.nasa.gov/gcn/ipn.html . CONTENT and QUALITY: These Notices contain the detection by one or two of the regular mission/instruments in the IPN constellation of spacecraft. There are quality flags indicating that each specific detection is "definitely", "probably", "possibly" and "definitely not" a GRB. Initially, only those detections with the "definitely" flag set will be distributed. Later, as experience determines, this threshold may be lowered to the "probably" category. (A total of about 200 gamma-ray bursts per year are detected by the IPN, but not all of them can be confirmed rapidly.) Note that it is possible that some SGR outbursts may be confused with cosmic GRBs at this stage. The expected occurance rate will be ~1/week for the "definitely" Timestamp-only Notices and ~1/month of the Annulus Notices. SEQUENCE: Initially, a single spacecraft makes a detection of countrate increase and determines it to be a burst (usually through lightcurve shape and spectral aspects). The instrument team sends a message to GCN containing the information to GCN, which then sends it out as Timestamp-only Notice. If, later, a second spacecraft (with a sufficiently different earth-centric baseline) makes a detection of the same burst, then a true IPN annulus is calculated. This annulus information is then sent to GCN, which then sends out an Annulus Notice. Currently, the combining of the two detections into an annulus is done manually in the IPN Team by various analyses. Eventually, this combining will be done automatically within GCN. ENVISIONED USE FOR THIS NOTICE TYPE: Since this type contains only a timestamp of a GRB (and sometimes an annulus on the sky), it is envisioned that this Notice type is suitable for those sites that want to time-correlate any detections in their instruments with those mission-instruments in the IPN network. (This might include not only wide-angle optical sky-survey cameras, but also neutrino, gravitational radiation, TeV detectors, although, of course, anybody is free to receive this Notice type.) Not all timestamp notices will be followed up with localization information; please contact Kevin Hurley and/or Valentin Pal'shin (khurley AT ssl.berkeley.edu, val AT mail.ioffe.ru) if you need further information on an event. FILTERING: Sites that have this type enabled will get both subtypes (timestamp-only and annulus) -- there is no subtype filtering. The ratio of timestamp to annulus is greater than 10. ACTION ITEM: If you want to receive this IPN_RAW Notice type, then reply to this email (that has your _sitename_ and config) to me (scott@milkyway.gsfc.nasa.gov), and I will enable it. EXAMPLES OF THE OUTGOING FULL-FORMAT EMAIL NOTICES: (Items in angle brackets (<>) are not part of the email format; they are just explanations of that line in the email.) (These IPN_RAW notices are also available in all the other email-based formats and in the socket packet format (see the sock_pkt_def_doc.html).) Example of a Time-only Notice: TITLE: GCN/IPN ANNULUS NOTICE NOTICE_DATE: Sun 24 Aug 08 16:48:40 UT NOTICE_TYPE: IPN Time_only TRIGGER_NUM: 0 <0 if unknown or not available> GRB_DATE: 14701 TJD; 236 DOY; 08/08/23 GRB_TIME: 31339.25 SOD {08:42:19.25} UT