TO: All GCN Sites 26 Feb 05 RE: Swift-XRT_Position Notices go Real-Time INTRO: This is the 4th announcement in the series of getting the Swift burst information into the GCN system; ref: 3nd, 14feb05 http://gcn.gsfc.nasa.gov/gcn/admin/gcn_swift3.txt 2nd, 21dec04 http://gcn.gsfc.nasa.gov/gcn/admin/gcn_swift2.txt 1st, 06nov04 http://gcn.gsfc.nasa.gov/gcn/admin/gcn_swift1.txt SWIFT-XRT_POSITION NOTICES DISTRIBUTED IN REAL-TIME: The Swift-XRT Instrument team has completed the initial phase of their on-orbit verification and is now ready to distribute the XRT-based Notices in real-time, ie no humans-in-the-loop delays. This automatic distribution will start Saturday, 26 Feb 05. This includes the following Notice types: SWIFT_XRT_POSITION // XRT Afterglow Position SWIFT_XRT_NACK_POSITION // XRT No Position found SWIFT_XRT_SPECTRUM // XRT Spectrum of afterglow SWIFT_XRT_IMAGE // XRT Image of afterglow SWIFT_XRT_LIGHTCURVE // XRT Lightcurve of afterglow XRT POSITION ERRORS: The initial alignment measurement of the XRT instrument to the Star Tracker boresight has been completed, and verified using steady-state sources ranging from sources near the XRT Image Mode detection threshold to Sco X-1. The positional accuracy has been shown to be 6 arcseconds at 90% containment (this is a conservative specification and will be improved as the XRT Team acquires more experience). SIGN-UP and REQUESTS FOR CONFIG CHANGES: From previous announcements, many GCN recipients have already signed up for the various Swift Notices. However, still some have not. (Your configuration is appended below.) Sites should take this opportunity to request that they receive which Swift-based Notices they want. And as always, requests for changes to any part of a site's configuration are always welcomed -- now, or any time in the future. Send those requests to: scott@milkyway.gsfc.nasa.gov (Replies to this announcement's email_address go to another place and may not be noticed for many days.) And when requesting a change to your configuration, please include your sitename (or some specific identifying information). There are 420 entries in the list, and I can not remember all of you. When I get a terse email like "Hi, this is Bob. Send me the Swift Notices.", it gets difficult to sort out. Just put a marker next to the items in your configuration (appended below) you want changed. NOTICE TYPES: There are 24 different types of information from the Swift mission. Since some of these Notices are of a sufficiently different type of content than previous missions (ie images, spectra, etc), people may need to study the web pages (see below) carefully to determine which types are suitable for their specific operation. Please note that 3 types are not yet available. Note that there 3 groups of messages: Flight-Generated: SWIFT_BAT_GRB_ALERT // BAT GRB ALERT SWIFT_BAT_GRB_POSITION // BAT GRB Position SWIFT_BAT_GRB_NACK_POSITION // BAT GRB No Position SWIFT_BAT_TRANS // BAT Transient Position SWIFT_BAT_GRB_LIGHTCURVE // BAT GRB Lightcurve SWIFT_FOM_OBSERVE // FOM decision about the merit check SWIFT_SC_SLEW // S/C decision about slewing or not SWIFT_XRT_POSITION // XRT Position of afterglow SWIFT_XRT_SPECTRUM // XRT Spectrum of afterglow SWIFT_XRT_IMAGE // XRT Image of afterglow SWIFT_XRT_LIGHTCURVE // XRT Lightcurve of afterglow SWIFT_XRT_NACK_POSITION // XRT did not find a position SWIFT_UVOT_DARKBURST // UVOT full-pixel image SWIFT_UVOT_FINDCHART // UVOT sifted-pixel image Ground Re-Processed: SWIFT_BAT_GRB_LIGHTCURVE_PROC // Ground processed version [NOT YET AVAIL] SWIFT_XRT_SPECTRUM_PROC // Ground processed version SWIFT_XRT_IMAGE_PROC // Ground processed version SWIFT_UVOT_DARKBURST_PROC // Ground processed version SWIFT_UVOT_FINDCHART_PROC // Ground processed version SWIFT_UVOT_POSITION // UVOT afterglow position Misc: SWIFT_BAT_GRB_POS_TEST // BAT GRB Position Test message SWIFT_POINT_DIR [NOT YET AVAILABLE] // Pointing Direction message SWIFT_FULL_DATA_INIT [NOT YET AVAILABLE] // Is the initial data set available SWIFT_FULL_DATA_UPDATE [NOT YET AVAILABLE] // Has the initial data set been updated CONTENTS and FORMATS: A detailed description of all the Swift Notices is contained in: http://gcn.gsfc.nasa.gov/gcn/swift.html and for the socket sites, the packets are defined in: http://gcn.gsfc.nasa.gov/gcn/sock_pkt_def_doc.html The Swift mission has packet types 60 through 84. The email/pager/cell sites are encouraged to also read the sock_pkt_def_doc web page, because the same fields that are in the socket packets also appear as the various "TOKEN: value" lines in the email-based distribution formats. Socket sites are also encouraged to look at the socket_demo program to understand the socket packet formats and the content -- there are generic packet unpacking routines therein. http://gcn.gsfc.nasa.gov/gcn/socket_demo.c Please note that both the sock_pkt_def_doc and the socket_demo.c have been updated (since the last announcement) with modified/improved interpretations of the flags bits. ATTACHMENTS: 1) For the full_email-based recipients, they can also select if they want to receive the various lightcurves, images, and spectra as attachments. There are only two choices: a) you select no attachments, or b) you get all the attachments (currently, there is no option to get, say, just the XRT_IMAGE Notice with the actual image attached, and get the XRT_SPECTRUM Notice without its spectrum attachment). These attachments are not big, so getting a couple of the Notice types with attachments that you do not particularly want will not be a burden on your email inbox. You also have to specify which format you want: FITS, GIF, JPEG, Postscript. 2) The BAT_LIGHTCURVE Notice type now has nearly all the formats implemented; the JPEG, GIF, and PS formats have been added to the FITS format. The TEXT format does not yet exist. All theother Notice types have the full compliment of attachment formats available. SCHEDULE: The plan for the 3 phases of availability is listed below. This announcement introduces the transition from phase 2 to phase 3 for the XRT Notices. 1) Delayed Circulars: Even though Swift launched on 20 Nov 2004, the fully automated phase of the GCN/Swift Notices (positions, images, spectra, & lightcurves) will not be immediately available. The Swift team will be performing an on-orbit check-out, during which the positions will not be made available to the public in real time (delays of 1-3 hrs). The positions will be distributed with some delay through the GCN Circulars. There are numerous cross-checks and calibrations that must be performed to guarantee the safety of the spacecraft & instruments and the accuracy of the burst Notices. (This phase is already happening.) 2) Delayed Notices: After some of the check-out period has happened, the positions (& the other information types) will be available and distributed through GCN Notices, also with some delay (0.3-2 hrs). (The official check-out interval is 135 days, however the distribution of positions may happen sooner if the various instrument teams develop confidence in their instruments sooner.) During the check-out period, if a burst is determined by the instrument teams to be of high enough confidence, then it will be distributed with some delay. (This phase is already happening.) 3) Real-Time Distribution: And then full automatic distribution will start. Full-auto means from Swift, through TDRSS, to GCN, out to the world; with no human intervention/inspection/processing in the loop. This announcement is for the start of this phase for the XRT-based Notices only. (The BAT-based Notices are already being distributed in real-time.) The full-auto (no delay) distribution for the UVOT Notices will start within 2-5 weeks. Sincerely, Scott Barthelmy NASA-GSFC, Code 661, Greenbelt, MD 20771 PHONE: 301-286-3106 (office) PHONE: 301-346-3733 (cell) FAX: 301-286-1684 (1st choice, -1682 2nd choice) EMAIL: scott@lheamail.gsfc.nasa.gov PAGER: 3013463733@mobile.att.net (by email, 200 characters max per message) WEB: http://gcn.gsfc.nasa.gov/gcn ///////////////////////// your current configuration ////////////////////////////