TO: All GCN Notice recipients RE: Fermi-GBM Subthreshold transients now available DT: 17 Jul 2017 INTRODUCTION: The GCN system has been modified to incorporate the distribution of Fermi-GBM Subthreshold transients. OCCURRENCE RATE: The expected rate will be about 70 per month. (During periods of Cyg X-1 activity, the rate will be ~270/month.) TIME DELAY: Given that the ground processing of the batched downlinked data, the time delays for this notice type will range from 0.5 to 6 hours. LOCATION ERROR: The location uncertainties are in the 10-40 deg range (radius, stat+sys, 68% containment). This uncertainty represents the quality of the online position reconstruction, and it is computed in real time for each transient. NOTICE TYPE, CONTENT, and PURPOSE: The Notices contain the date, time, transient number, the RA,Dec of the largest location probability, and the uncertainty of that location. The measure of the duration of the transient which is the delta_time for the interval for which the search algorithm found the highest statistical significance. A "type_class" flag indicating if the event is "short" or "long". A "spectral class" flag indicating if the event spectrum is "hard" or "soft". This field is only really defined for events with sufficient signal and otherwise has the default value of "1" hard. Events of reliability 2 and some events of higher reliability have insufficient signal for the evaluation. A soft flag indicates that the transient is most likely not a GRB. A "reliability" value (running from 1 to 10) indicating the likeliness that this transient is astrophysical. Over the months of April to July, there were 144 Notices produced, of which: All 144 had "type_class" of "short", and "spectral class" of "hard". This is because the analysis pipeline producing the "longs" is not yet ready for release so all 144 "shorts" have come from the "short" pipeline. The "long" pipeline is expected to be ready in a few months. And 80% had reliability "2" (low), 10% had "5" (medium), and 10% were "8" (high reliability). Included are URLs for (a) a Healpix FITS file of the location probability on the sky, (b) a PNG file showing that map, and (c) a URL the lightcurve of the transient. (The URLs point to the GCN website where they can be downloaded via wget/curl/etc.) ACTION ITEM: If, after reviewing the information below, you want to receive these FERMI_GBM_SUBTHRESHOLD notices, please send me a request to have them enabled. You can do this by forwarding this email (which has your sitename identifier) to sbarthel@milkyway.gsfc.nasa.gov . OR You can go to http://gcn.gsfc.nasa.gov/gcn/config_builder.html and select "#2 Modify an existing config" (and type in your sitename). You can also take this opportunity to make other changes to your configuration. ARCHIVE STORAGE: The GCN/FERMI_GBM_SUBTHRESHOLD Notices are archived within the GCN website in the Table of GBM SUBTHRESHOLD Notices: https://gcn.gsfc.nasa.gov/gcn/fermi_gbm_subthresh_archive.html MORE INFORMATION: Can be found at: http://gcn.gsfc.nasa.gov/gcn/fermi.html NOTICE EXAMPLE: Here is an example of a full-format email Fermi-GBM_SUBTHRESHOLD: ///////////////////////// Fermi-GBM e-mail format ////////////////////////////// TITLE: GCN/FERMI NOTICE NOTICE_DATE: Tue 04 Jul 17 14:45:26 UT NOTICE_TYPE: Fermi-GBM SubThreshold TRANS_NUM: 520865109 FULL_ID_NUM: 520865109.040000 TRANS_RA: 304.080d {+20h 16m 19s} (J2000), 304.306d {+20h 17m 13s} (current), 303.435d {+20h 13m 44s} (1950) TRANS_DEC: -1.030d {-01d 01' 47"} (J2000), -0.975d {-00d 58' 30"} (current), -1.185d {-01d 11' 04"} (1950) TRANS_ERROR: 25.64 [deg radius, stat+sys, 68% containment] TRANS_DURATION: 0.703 [sec] TRANS_DATE: 17938 TJD; 185 DOY; 17/07/04 TRANS_TIME: 45904.04 SOD {12:45:04.04} UT EARTH_ANGLE: 124.50 [deg] SPECTRAL_CLASS: 1 (0=soft, 1=hard) TYPE_CLASS: 0 (0=short, 1=long) RELIABILITY: 2 (2=low, 5=medium, 8=high) HEALPIX_URL: https://gcn.gsfc.nasa.gov/notices_gbm_sub/gbm_subthresh_520865109.040000_healpix.fits MAP_URL: https://gcn.gsfc.nasa.gov/notices_gbm_sub/gbm_subthresh_520865109.040000_map.png LC_URL: https://gcn.gsfc.nasa.gov/notices_gbm_sub/gbm_subthresh_520865109.040000_lc.pdf SUN_POSTN: 103.92d {+06h 55m 42s} +22.82d {+22d 49' 09"} SUN_DIST: 150.52 [deg] Sun_angle= 10.6 [hr] (West of Sun) MOON_POSTN: 231.84d {+15h 27m 21s} -13.51d {-13d 30' 33"} MOON_DIST: 72.73 [deg] MOON_ILLUM: 82 [%] GAL_COORDS: 42.02,-19.29 [deg] galactic lon,lat of the burst (or transient) ECL_COORDS: 306.15, 18.24 [deg] ecliptic lon,lat of the burst (or transient) COMMENTS: Fermi-GBM Subthreshold. COMMENTS: This Notice was ground-generated -- not flight-generated. //////////////////////////////////////////////////////////////////////////// The socket packets contents can be found at: http://gcn.gsfc.nasa.gov/gcn/sock_pkt_def_doc.html REMINDER OF RECENT ADDITIONS TO GCN: In case you have missed them, here is a brief list of the most recent additions to the GCN system. You might consider signing up for these Notice types as well. The full announcements/descriptions for each of these can be found at: http://gcn.gsfc.nasa.gov/gcn/whats_new.html AMON_ICECUBE_EHE (July 2016) // ICECUBE Extremely High Energy Events AMON_ICECUBE_HESE (Apr 2016) // ICECUBE High Energy Starting Events CALET_LC (Mar 2016) // The Flight- & Ground-produced CALET-GBM lightcurves SNEWS (Dec 2015) // SNEWS notice type added (real and test forms) Redundant Ver 2.0 VOEvent Server // A 2nd/redundant VOEvent (Version 2.0) was added to GCN system FERMI_GBM LOCATION MAP (Apr 2014) // URL added to notices that contain pointer to burst location sky map FERMI_GBM_LIGHTCURVES (Apr 2014) // URL added to notices that contain pointer to burst lightcurve FERMI_LAT_OFFLINE (Feb 2014) // Human-in-the-loop ground processing to get GRB positions IPN_RAW resumes (Aug 2012) // IPN Team resumes producing the IPN_RAW notices SWIFT_BAT_SUB_SUB_THRESHOLD (May 2012) // Swift-BAT Triggers with very low significance; use for temporal coincidences Sincerely, Scott Scott Barthelmy NASA-GSFC, Code 661, Greenbelt, MD 20771 PHONE: 301-286-3106 (office) CELL: 301-346-3733 EMAIL: scott@lheamail.gsfc.nasa.gov PAGER: 3013463733@cingularme.com WEB: http://gcn.gsfc.nasa.gov/gcn