gcn: recent & future improvements taka sakamoto for scott barthelmy gsfc apr 2009, egypt...
TRANSCRIPT
GCN:Recent & Future
ImprovementsTaka Sakamoto
forScott Barthelmy
GSFCApr 2009, Egypt
Outline:1) GCN System Description.
2) GCN Status and Statistics.3) Recently Added New Functions and Features.4) Near-Future Functions and Features.
Egypt, Apr09
What is GCN?It’s “The Gamma ray bursts Coordinates Network.”
Egypt, Apr09
Description of the GCN System
• GCN is a system of programs with 3 basic activities:– NOTICES: Collect GRB locations from various s/c and
distribute them to interested parties.– CIRCULARS: Collect reports from burst follow-up observers &
distribute them to the GRB community. (Easy, Cheap, and Fast)
– REPORTS: Collect full/detailed/final reports from burst follow-up observers & distribute them to the GRB community.
• These 3 compliment each other– Notices for the real-time observation needs.– Circulars for the humans-in-the-loop after-the-observations.– Reports provide the final (full analysis) reference.
Egypt, Apr09
Distribution Methods• Internet Socket (for the robotic instruments)
– 4 msec to write to 65 sockets– 0.01-2.0 sec roundtrip travel time (~0.3 sec 98-percentile)– Each end can break/make the connection at will; there are re-try loops.
– Software provided (socket_demo.c from the web site).
• E-mail (for the human-based operations)– 9 msec to generate the ~250 email commands– 40 sec to execute those commands– 0.1-2 min for delivery
• Pagers & Cell-phones (when you’re away from operations)– Uses e-mail– Multiple formats for the various service providers: long, short & subject-only.
• Web site (“pull” technology)– Archive all the Notices & Circulars, LightCurves, Images, Spectra, etc.
– Updated by T+3 min.
Egypt, Apr09
Status and Statistics• 561 Sites (Notices):
– 119 socket-based (~65 routinely connected)– 442 email-based (full-format, pager, cellphone)
• 995 Circulars/Reports recipients• Swift Statistics:
– 409 bursts detected & distributed (as of 25mar09)
– False Positive Rate is 2% (since after May 06)
• Other Statistics:– 110 Fermi-GBM bursts– 6 Fermi-LAT bursts– 52 INTEGRAL bursts– 8 SuperAGILE bursts– 21 IPN_Raw bursts
Egypt, Apr09
New: FERMI & AGILE
• FERMI:– GBM Notices available (as of 17 Oct 08).
• Alert Heads-up; timestamp and trigger number.
• Flight_Position 1-N on-board calculated position.• Ground_Position 1-N ground-calculated position.
– Propagation delay ~8-10 sec (only 0.3 sec within GCN).
– LAT Notices available (as of 28 Feb 09):• Updated_Position 1-N updated on-board calculated positions.
• AGILE (as of July 08):– Wakeup 0-1 per burst, initial on-board position.
– Ground-calc_Position0-1 per burst, improved gnd algorithms.
– Refined_Position 0-1 per burst, human-in-the-loop.
Egypt, Apr09
New (Apr 08): Swift-BAT Slew Bursts
• Slew Sources:– GRBs found during the time when Swift is slewing.
– Capture BAT event-by-event data during slews.– Processed on the ground (1-7 hrs later) to find the bursts.
– Developed by Antonio Copete et al (Harvard).– Location uncertainties 3-4 arcmin.– 9 GRBs found and distributed.– Swift TOOs are typically done to get XRT/UVOT results• 2-12 hrs after the burst
Egypt, Apr09
New (Jun 08): Auto-Processed Lightcurves• URL: http://gcn.gsfc.nasa.gov/gcn/swift_gnd_ana.html• BAT & XRT lightcurves (UVOT images & spectra in the future)– BAT: Mask-weighted (background subtracted)– XRT: On-going afterglow– Automatically processed and updated as more data is downlinked.– Available in plots and in text (64-msec binning; can be rebinned to suit your needs).
– Suitable for inclusion into your papers (citations to Swift encouraged).
Example BAT PlotExample XRT Plot
Example Text file (XRT)
Egypt, Apr09
New (Apr 08): VOEvents• As part of the IVO Association and the VOEvent subgroup, GCN has developed a new way of distributing burst & transient information.
• It uses the VOEvent protocol and formats.
• XML messages for all the GCN Notice types are being distributed.– Through eSTAR; and soon NOAO & Caltech and GCN-direct!
Egypt, Apr09
New (Nov 07): Improved Site Configuration• Webpage-based configuration specification.
• Works for:– 1) a brand new site creation.
– 2) requesting a modification to an existing site.
– 3) just getting an english-version listing of your own site on your own demand.
URL: http://gcn.gsfc.nasa.gov/config_builder.html
Egypt, Apr09
New (Oct 07): Near-by Galaxy Associations• Full-format emails now contain a comment when the burst location is in a near-by galaxy.
• NGC catalog used:– Only the 4875 galaxies that have sizes specified are included.
– All non-galaxy entries were eliminated (nebulae, clusters, etc):
• Since there is a <0.05% probability that this would happen by chance, the association of a given burst with the galaxy is almost certainly real.– In 376 Swift-BAT GRBs; that’s a total of only a 19% chance.– GRB 980425 was in a close galaxy (z=0.0085).
• Two scenarios are tested and reported:
BAT Error CircleGalaxy
P1
P2
Galaxy (eg M31)Major Dia.
Bursts Position
Position circle smaller than GalaxyGalaxy smaller & inside Position Circle
Egypt, Apr09
New (May 07): Bright Star Notification
• Full-format emails now contain a comment when there is a bright star near the burst location.– There are 9054 stars in the search dbase,– Greater than 6.5 mag.– Closer than 12 arcmin (radius).– Actual mag and actual distance to the burst location are also specified.
– Done for all burst_position-containing Notice types.
• This helps follow-up observers know when there will be a bright star complicating their observations.
Egypt, Apr09
New (Oct 06) : REPORTS• Are more detailed than the Circulars.• Are more complete; more accurate.• 168 GRBs have these Reports (all of them Swift so far)
• Encourage non-Swift observers to submit Reports.
Egypt, Apr09
Near-Future: Swift-BAT Subthreshold
• BAT is currently testing triggers below the normal 6.5 sigma level. ~60 triggers to date; 1 was real GRB.
• These extra triggers are a separate Notice type within GCN (so that recipients can elect to separately enable them).
• ~2 triggers per day (the above-threshold rate is 2 per week).
• There are two distribution times:– Immediately for the SubThreshold type (to those that sign up).• Lots of fasle-positives; suitable for robotic telescopes.
– Delayed (5-20 min) until the XRT_POS message can be processed by the UL auto-pipeline. If an XRT position is found, then GCN will “promote” the trigger to a BAT_POS-series of Notices and distribute them to the world.• If you have signed up for BAT/XRT_Pos, then you will get these too.
Egypt, Apr09
New: Misc Stuff• IPN_RAW Notices (Sep 08):– Timestamp-only: GRB detections by a single s/c– Annulus: GRB detection by 2 s/c– This is the first step in automating the cross-correlations.
• SIMBAD-NED Search Notices (Aug 08)– Available for the small-error-circle Position Notices (Swift, AGILE, Fermi-LAT, INTEGRAL)
• MIME-compliant/capable Circulars (Sep 08)– Strips out all that messy HTML -- just the true text distributed.
• Handle Circulars Subject-lines that were long– Wrapping now handled correctly -- no longer truncated.
• “socket_demo.c” updated for AGILE & Fermi types. (Sep 08)
Egypt, Apr09
POINTING DIRECTION NOTICES
• Some Missions provide their observing plan pointing direction as a function of time.
• GCN has turned this information into Notices.
• This allows robotic telescopes to “follow along”:– This minimizes slewing time by minimizing slew distance.
– It allows for “pre” burst trigger_time images.
• Missions with Pointing_Dir Notices:– Swift– INTEGRAL– AGILE (new as of Jul 08)– FERMI (new as of Feb 09)
Egypt, Apr09
Data Products by Mission
Mission N_Inst N_Notices
Comment
GRO 3 6 original
ALEXIS 1 1 Ex-UV
HETE 2 3 1st r-t & small
beppoSAX 1 1
RXTE 2 4 GRBs & Trans
IPN “1” 2 not r-t
INTEGRAL 1 6+1
Swift 3 14+2+5 w/Attachments
AGILE 1 3
Fermi 2 3+1 GBM is public
Egypt, Apr09
Backup Slides
Egypt, Apr09
How GCN Collects Inputs
• Interface Programs: – Sockets: integral_ibas_receiver, swift_tdrss_receiver, and fermi_receiver
– Email: procmail deposits in import dir gromain periodic checks
– Cmd_Files: manually force Test Notices (also param changes)
gromain(GCN)
swift_tdrss_receiver
integral_ibas_receiver
~/import/
ws_sim
ws (gsfc)
~/import/
~/import/
~/import/
ibas (Europe)
gnd proc s/w
fermi_receiver (GSFC)
theworld
Email:IPNAGLERXTE
BAP (gsfc)
Egypt, Apr09
Socket Packet Contents
• 160 bytes, 40 dwords
• Type number• Serial number• Packet Time• RA, Dec, Error• Intensity• Trigger_ID Flags• Misc Flags
• Plus other type-specific items (box shape, URL, etc)
Nearly the same content, and the same format across all types.
Egypt, Apr09
Daily Socket Connection Report (1of2)For the UT day 12/10 2005:
0 failed attempts to connect were made. 1 successful connections were made. 1 disconnects from the GCN end.
1547 Total packets sent (types 2-4,39,40-44,51-55,60-84): 0 Type 2 sent (Test Coords) out of 8 1437 Type 3 sent (Imalive) out of 1437 1 Type 4 sent (Kill pkts) out of 1 0 Type 39 sent (IPN_POS) out of 0 0 Type 40 sent (HETE_ALERT) out of 0 0 Type 41 sent (HETE_UPDATE) out of 0 0 Type 42 sent (HETE_FINAL) out of 0 0 Type 43 sent (HETE_GNDANA) out of 0 8 Type 44 sent (HETE_TEST) out of 8 31 Type 51 sent (INTEGRAL_PNTDIR) out of 39 0 Type 52 sent (INTEGRAL_SPIACS) out of 39 0 Type 53 sent (INTEGRAL_WAKEUP) out of 39 0 Type 54 sent (INTEGRAL_REFINED) out of 39 0 Type 55 sent (INTEGRAL_OFFLINE) out of 39 0 Type 60 sent (SWIFT_BAT_GRB_ALERT) out of 0 1 Type 61 sent (SWIFT_BAT_GRB_POS_ACK) out of 1 0 Type 62 sent (SWIFT_BAT_GRB_POS_NACK) out of 0 1 Type 63 sent (SWIFT_BAT_GRB_LC) out of 1 1 Type 65 sent (SWIFT_FOM_2OBSAT) out of 1 1 Type 66 sent (SWIFT_FOSC_2OBSAT) out of 1 1 Type 67 sent (SWIFT_XRT_POSITION) out of 1 0 Type 68 sent (SWIFT_XRT_SPECTRUM) out of 2 1 Type 69 sent (SWIFT_XRT_IMAGE) out of 1 1 Type 70 sent (SWIFT_XRT_LC) out of 1 0 Type 71 sent (SWIFT_XRT_CENTROID) out of 0 1 Type 72 sent (SWIFT_UVOT_DBURST) out of 1 1 Type 73 sent (SWIFT_UVOT_FCHART) out of 1 0 Type 74 sent (SWIFT_FULL_DATA_INIT) out of 0 0 Type 75 sent (SWIFT_FULL_DATA_UPDATE) out of 0 0 Type 76 sent (SWIFT_BAT_GRB_LC_PROC) out of 0 0 Type 77 sent (SWIFT_XRT_SPECTRUM_PROC) out of 2 0 Type 78 sent (SWIFT_XRT_IMAGE_PROC) out of 1 0 Type 79 sent (SWIFT_UVOT_DBURST_PROC) out of 1 0 Type 80 sent (SWIFT_UVOT_FCHART_PROC) out of 1 0 Type 81 sent (SWIFT_UVOT_POS) out of 0 0 Type 82 sent (SWIFT_BAT_GRB_POS_TEST) out of 8 62 Type 83 sent (SWIFT_POINTDIR) out of 62 0 Type 84 sent (SWIFT_BAT_TRANS) out of 0 0 Were received back with some sort of error.
//////////// RECORD OF PROGRAM OPERATIONS /////////////////////05/12/10 19:26:30.472 GMT: Starting gromain.
//////////// RECORD OF SOCKET OPERATIONS //////////////////////05/12/10 19:25:10.983 GMT: Attempting to send KILL packet to XYZ...05/12/10 19:25:11.093 GMT: The shutdown of XYZ worked OK.05/12/10 19:26:31.263 GMT: Client socket to xyz.univ.edu XYZ is up.
//////////// RECORD OF PACKET ERRORS //////////////////////////There were no packet errors today.
Egypt, Apr09
Daily Report: (2of2) Histo of Roundtrip Times:
All Packets
//////////// HISTOGRAMS OF ROUNDTRIP TIMES ////////////////////Attached below are histograms of the roundtrip travel timesof the packets between the GCN system (capella) and SLOTISthat were received back in the proper order & with valid contents.The range of the histos is from 0.00sec to 100sec with0.25sec per bin resolution. Underflows (there should not be any)and overflows are also tabulated.The 6 histos are for the 4 packet type subclasses (0,1,2,3): 0) All_Position_Notices+INTEGRAL_Test (that pass your filter criteria), 1) All_Non-Pos_Swift_Notices. 2) All_Test_Notices(Type=2&44) (if enabled), 3) Type=Imalives (1440+-few per 24 hrs). 4) Type=<all_types>, 5) Type=<all_types_from_all_sites>.
Header[5]: Roundtrip of All pkt Types for all sites for 12/10 UT
Scale[cnts/star]=482.22 Binning[value/chan]=0.25 Comprs[chan/bin]=1 User=0
VAL CNTS CUMCNTS
Underflow(<0.00)= 0.0
--------------------------
0.00 26522.0 26522.0 *******************************************************
0.25 24488.0 51010.0 ***************************************************
0.50 7675.0 58685.0 ****************
0.75 7209.0 65894.0 ***************
1.00 4472.0 70366.0 **********
1.25 892.0 71258.0 **
1.50 461.0 71719.0 *
1.75 144.0 71863.0 *
2.00 63.0 71926.0 *
2.25 10.0 71936.0 *
2.50 12.0 71948.0 *
2.75 12.0 71960.0 *
3.00 38.0 71998.0 *
3.25 9.0 72007.0 *
3.50 65.0 72072.0 *
3.75 8.0 72080.0 *
4.00 5.0 72085.0 *
4.25 33.0 72118.0 *
4.50 31.0 72149.0 *
4.75 3.0 72152.0 *
5.25 4.0 72156.0 *
5.50 6.0 72162.0 *
5.75 5.0 72167.0 *
6.00 77.0 72244.0 *
6.50 36.0 72280.0 *
6.75 1.0 72281.0 *
7.00 2.0 72283.0 *
7.25 3.0 72286.0 *
8.00 30.0 72316.0 *
8.50 1.0 72317.0 *
9.00 1.0 72318.0 *
9.50 28.0 72346.0 *
10.25 1.0 72347.0 *
14.00 1.0 72348.0 *
15.25 2.0 72350.0 *
16.25 1.0 72351.0 *
18.25 1.0 72352.0 *
22.75 1.0 72353.0 *
30.50 1.0 72354.0 *
31.75 1.0 72355.0 *
33.50 1.0 72356.0 *
36.50 1.0 72357.0 *
39.00 1.0 72358.0 *
40.25 1.0 72359.0 *
45.75 1.0 72360.0 *
46.25 1.0 72361.0 *
57.25 1.0 72362.0 *
57.50 1.0 72363.0 *
--------------------------
Overflow(>100.00)= 0.0
Egypt, Apr09
Swift Data Products• BAT: Position and Lightcurve 15-30 sec
• XRT: Position (or nack) and Image (2x2’) 80-120– Spectrum and Lightcurves on the web page
• UVOT: Image and SourceList 300-400– 200 sec V band, 2.7x2.7’ and 8x8’– Raw and Processed forms
• S/C Observe and Slew (or not) 15-30• S/C Pointing Direction (so you can follow along)• Test
• Circulars on each burst:– 1st has BAT/XRT/UVOT initial findings & interpretation.– 2nd has “refined” results & analysis by each instrument.
Egypt, Apr09
History of Swift in GCN
• 20 Nov 04 Swift Launch• 17 Dec 04 First distribution of BAT GRB Position
– 16.5 hrs delayed; later ones were delayed by only 2-4 hours.
• 17 Feb 05 First real-time distribution of BAT GRB Position
• 19 Mar 05 First real-time distribution of XRT GRB Position– enabled on 26 Feb 05.
• 25 Aug 05 First real-time distribution of UVOT Images
• 12 Jan 06 Multiple UVOT images (up to 4 per trigger)• 10 Apr 06 UVOT Positions
– semi-realtime, T+10-30 min, humans in the loop.
Egypt, Apr09
Email & Pager Format Examples
Nearly the same content, and the same format across all types.
Can have attachments.Back
TITLE: GCN/SWIFT NOTICENOTICE_DATE: Sun 01 Mar 09 06:56:11 UTNOTICE_TYPE: Swift-BAT GRB PositionTRIGGER_NUM: 344582, Seg_Num: 0GRB_RA: 338.140d {+22h 32m 34s} (J2000), 338.248d {+22h 33m 00s} (current), 337.552d {+22h 30m 13s} (1950)GRB_DEC: +26.642d {+26d 38' 32"} (J2000), +26.689d {+26d 41' 22"} (current), +26.384d {+26d 23' 03"} (1950)GRB_ERROR: 3.00 [arcmin radius, statistical only]GRB_INTEN: 9699 [cnts] Image_Peak=997 [image_cnts]TRIGGER_DUR: 1.024 [sec] TRIGGER_INDEX: 148 E_range: 25-100 keVBKG_INTEN: 31402 [cnts]BKG_TIME: 24939.46 SOD {06:55:39.46} UTBKG_DUR: 8 [sec]GRB_DATE: 14891 TJD; 60 DOY; 09/03/01GRB_TIME: 24955.14 SOD {06:55:55.14} UTGRB_PHI: -61.91 [deg]GRB_THETA: 35.30 [deg]SOLN_STATUS: 0x3RATE_SIGNIF: 95.33 [sigma]IMAGE_SIGNIF: 21.68 [sigma]MERIT_PARAMS: +1 +0 +0 +0 +2 +7 -100 +0 -82 +0 SUN_POSTN: 342.30d {+22h 49m 12s} -7.51d {-07d 30' 27"}SUN_DIST: 34.42 [deg] Sun_angle= 0.3 [hr] (West of Sun)MOON_POSTN: 27.85d {+01h 51m 24s} +17.00d {+17d 00' 13"}MOON_DIST: 46.76 [deg]MOON_ILLUM: 19 [%]GAL_COORDS: 88.19,-26.70 [deg] galactic lon,lat of the burst (or transient)ECL_COORDS: 351.30, 32.94 [deg] ecliptic lon,lat of the burst (or transient)
GCN:Recent & Future
Improvements
Scott BarthelmyGSFC
Apr 2009, Egypt
Outline:1) GCN Status and Statistics.2) Recently Added New Functions and Features.3) Near-Future Functions and Features.
Egypt, Apr09
BAT Lightcurves (1of2)
GRB 051105
GRB 051111
GRB 051109A
GRB 051210
No slew -- Moon constraint
Egypt, Apr09
BAT Image Trigger LCs (2of2)
Slew at T+200sec
No slew -- Sun constraint
No slew -- Chance coincidence
No slew -- Match X 2127+119
Missing the 1st part
Egypt, Apr09
XRT Images (2x2’)
CosmicRay
GRB050421
GRB 051227GRB 060105
PSF=7.6 pixHPD
Egypt, Apr09
XRT Spectra & LightcurveGRB 051221
GRB 051210
Egypt, Apr09
Raw UVOT Image & Source List
2.7x2.7 arcmin 8x8 arcmin
Raw = no coordinates, no catalog matching
Egypt, Apr09
Processed UVOT Image & Source List
sw00173904_0274uvot_field_image.ps.gz10-100 sec after the raw versions.
BAT Er
ror Ci
rcle,
90+% C
L
2.7x2.7 arcmin 8x8 arcmin
UVOT Source ListUVOT Image
Egypt, Apr09
UVOT SourceList Catalog & GRB 050922C Afterglow
Candidate
Egypt, Apr09
163136 “sky” Source List
fv ds9
subarrays are blurred/enlarged
Egypt, Apr09
Swift GRBs Web Table
Archive of the Notices.Get plots of lightcurves & spectra, images (GIF, JPEG, PDF, PS).Get the FITS files.
Egypt, Apr09
BACKUP and DUP SLIDES
Egypt, Apr09
Clipped from fv
Egypt, Apr09
UVOT Catalog of Image (GRB 051109)
Egypt, Apr09
Filtering Methods• Notice Type
– Swift, INTEGRAL, AGILE, FERMI, IPN, RXTE, ….– Sub-type selection (instruments, saw/no_saw, etc)
• Visibility– All, Visible, Nighttime, and Customized
• Location Uncertainty Size– 1 arcsec to 360 deg (match your FOV/tiling capability)
• Time Delay (time since burst)– 1 sec to 40 days
• Trigger_ID– Is this a real GRB or something else (noise, hard x-ray transient)
• Sites get the logical-AND of all 5 filtering conditions
• Special filtering to accommodate mission-teams
Egypt, Apr09
Example of GCN Circular
TITLE: GCN CIRCULARNUMBER: 8778SUBJECT: GRB 090102: GRT Optical ObservationDATE: 09/01/04 17:13:41 GMTFROM: Takanori Sakamoto at NASA/GSFC <[email protected]>
T. Sakamoto (UMBC/GSFC), D. Donato (ORAU/GSFC), N. Gehrels (GSFC), T. Okajima (JHU/GSFC), T. N. Ukwatta (GWU/GSFC), Y. Urata (Saitama U), C. Wallace (FGCU) We observed the field of GRB 090102 detected by Swift (trigger #338895; Mangano et al., GCN #8762) with the 14-inch Goddard Robotic Telescope (GRT) located at the Goddard Geophysical and Astronomical Observatory (http://cddisa.gsfc.nasa.gov/ggao/). Ten set of 5 sec and five set of 10 sec and 30 sec exposures were taken in the R filter starting from Jan. 2 03:11:58 (UT) about 16.2 min after the trigger. We do not detect the optical afterglow (Klotz et al., GCN #8761, Mangano et al., GCN #8762) both in the individual images and the combined image. The estimated three sigma upper limit of the combined image (total exposure of 250 sec) is ~17.9 mag using the USNO-B1 catalog.
back
Egypt, Apr09
Example of GCN Report
back
Egypt, Apr09
GCN Swift Ground Analysis Pageback
TLC BA MainPage
Egypt, Apr09
TLC (TDRSS Light Curve)back
Egypt, Apr09
BA script (BAT)Sky image
Light curve (1s, 64ms, 10s/SNR=5)
Spectrum(PL, CPL, Band)
back
- Fluence- Peak flux- T90/T50-…..
Egypt, Apr09
XRTLight curve
Hardness ratio
Image
back