VOEventNet: A Portal to Astronomical Transients

Roy Williams
LOFAR and the Transient Radio Sky, Amsterdam, December 2008

Transcript

1. skyalert.org SkyAlert.org
 Real-time Astronomical Events
 for You and your Robot Roy Williams California Institute of Technology (and Alasdair Allen, Exeter UK
 Scott Barthelmy, NASA
 George Djorgovski, Caltech
 Andrew Drake, Caltech
 Matthew Graham, Caltech Ashish Mahabal, Caltech
 Rob Seaman, NOAO)
2. skyalert.org VOEventNet: global
 Skyalert.org: Caltech+NOAO Caltech eStar Exeter NOAO Tucson Pairitel Berkeley Palomar P60 Caltech Catalina RTS UAriz Liverpool Telescope La Palma UKIRT Hawaii Stream Author Publisher Repository Relay Followup Subscriber Faulkes Hawaii/Australia OGLE III Poland GCN @ NASA/GSFC SWIFT Fermi Integral AGILE CTIO/KPNO LCOGT MOA AAVSO PannSTARRS skyalert.org
3. skyalert.org Transient Sources in the Sky •  Satellites (10000" per hour) •  Near Earth Objects (3000" per hour) •  Main Belt Asteroids (10" per hour) •  Jupiter & Saturn •  Comets •  Trans-Neptunians (1" per hour) •  Radial-velocity planet searching (10 - 100 pc) •  Planet transit searching (100 - 10000 pc) •  M-dwarf flares •  Microlensing + CV + novae (100000 pc) •  Pulsar glitches and RRAT •  RR Lyrae in the galactic halo •  Extragalactic microlensing (10 Mpc) •  Supernovae •  Black hole inspiral and merger •  AGN and blazar glitches •  Gamma Ray Bursts •  And …… NOT YET THOUGHT OF ....?
4. skyalert.org Supernova in Antennae NASA funded event stream Catalina Sky Survey
5. skyalert.org Microlensing Optical transients Radio transients X-ray transients Gamma transients Grav. waves Neutrinos Followup Scheduler Telescope Astronomers Amateurs Students Telescope Telescope Event Authors Event Subscribers International GCN Broker Annotation from archives Events and annotation disseminated to subscribers in real time with intelligence
6. skyalert.org events streams users triggers annotation & comment Web application system Loaders Annotators SDSS, USNOB, etc Subscription
 Alert
 Triggers Rich web
 application Event
 digester authors subscribers Alerts: Email, IM, SMS, TCP, etc Rich web Queries Subscriptions Wiki Telescope Skyalert architecture
7. skyalert.org Reporting (Pre-VOEvent) •  Who? Babylonian Astronomical Diary •  What? The comet which previously had appeared in the east in the path of Anu in the area of Pleiades and Taurus •  Where? to the west […] and passed along in the path of Ea in the region of Sagittarius, 1 cubit in front of Jupiter, 3 cubits high toward the north […] •  When? Month VIII, SE 148 
 (lunar month beg. 21 October 164 BC) •  How? By eye •  Why? Celestial divination Slide courtesy M Graham
8. skyalert.org Reporting (Pre-VOEvent) Write natural language Send letter Boston or Montreal Transcribe data correctly! Read and decide to follow-up Transcribe data correctly Send letter to telescope ….etc etc How about automation?
9. skyalert.org Reporting (Pre-VOEvent) •  All human-based •  Data entry problems •  Multiple site monitoring ATEL CBAT GCN SN
 factories Panstars
10. skyalert.org VOEvent Paradigm •  Event aggregation •  Personal subscription •  Annotation and portfolio •  Decision and followup •  Automated actionable intelligence ATEL CBAT GCN SN
 factories Panstars VOEvent
11. skyalert.org First cut: All or nothing
 voeventnet.org Jabber/XMPP* HTML RSS* KML TCP socket*
12. skyalert.org Google Sky has VOEvents
13. skyalert.org What is VOEvent •  XML document according to VO-standard •  Who, Wherewhen, Why, Params •  Each event belongs to a Stream –  Eg SWIFT, OGLE, LOFAR I hope, ... •  Author, Subscriber, Repository functions •  Information not Imperative •  Follow-ups are other VOEvents • Connected in citation graph to form Portfolio
14. skyalert.org VOEvent Structure •  Who •  Publisher, Contact, etc •  Subscribers will use AuthorID to select •  WhereWhen •  Can be simple eg RA, Dec, UTC, positionError •  Can be sophisticated, eg multiple frames, near objects, etc •  What •  Hierarchy of named parameters •  Units, Semantic type (UCD) •  References, Descriptions •  How •  How was the evidence gathered: camera, telescope, etc •  Why •  probability list of interpretation –  supernova, comet, asteroid, ..... •  Citation •  Link to other VOEvent: Followup, Supercede, Retraction, •  Link to support data
15. skyalert.org Stream as Event Template stream event
16. skyalert.org Streams in VOEventNet
17. skyalert.org Access Control •  Each stream has Unix-like access control –  read and write –  owner, group, world •  Without access right ... • Cannot see old events • Cannot get alerts owner group permission
18. skyalert.org Streams in Skyalert
 … past, present & future Catalina Sky Survey Fermi GCN Circulars Integral MOA microlensing OGLE microlensing Swift AAVSO alerts ASKAP Allan Telescope Array (ATA) IceCube neutrinos LIGO/Virgo LOFAR Large Synoptic Survey Telescope (LSST) Murchison Widefield Array Pan-STARRs SkyMapper Berkeley SN factory Essence SN survey Palomar-Quest SDSS supernova
19. skyalert.org AAVSO Timely Publications Special Notices includes announcements on interesting and/or rare stellar activity that don't involve coordinated campaigns. The goal is for the ASN to be quick and brief. Alert Notices Detail discoveries of new novae, unusual variable star activity, and requests by astronomers for simultaneous AAVSO observations. Massive radio burst: amateur telescope spots bright optical afterglow minutes later
20. skyalert.org Event can have complex data This light-curve is anomalous! -- B. Obama
21. skyalert.org Citation makes Portfolio •  An event can cite another <Citations><EventID cite=”followup"> ivo://gcn.nasa/VOEvent#hete_389241a_20050808_230931 </EventID> </Citations> •  Observations can be federated by mutual citation followup annotation followup observation portfolio
22. skyalert.org Event Cascade event trigger rule subscriber (telescope) subscriber (human) subscriber (annotator program) author event event portfolio comment trigger rule trigger rule
23. skyalert.org SDSS archive uMag gMag uCutoutURL gCutoutURL Catalina Sky Survey mag1 mag2 mag3 asteroidness stellarity cutoutURL Berkeley lightcurves lightcurveURL probSN probCV Palomar 60” follow-up gmag rmag ipmag zpmag datapackageURL 21.42 20.96 http://..... http://..... 19.34 19.32 19.39 1% 97% http://..... http://...... 87% 12% 19.07 18.03 18.57 18.94 http://..... Streams (event template) Events (template instance) Annotation
 (linked data) Original detection Archive follow-up Archive follow-up Telescope follow-up joint rule Triggers (for action) subscribers
24. skyalert.org Annotator examples •  add intelligence –  input is lightcurve, –  output is likelihood for known object classes •  get data –  input is position –  output is SDSS catalog and cutouts and nearest galaxy •  telescopic followup –  connect skyalert to scheduler –  output is hopefully reduced data
25. skyalert.org Building an Annotator •  Define input and output streams –  Param • name, unit, semantics (UCD), description –  Data objects • FITS, VOTable, txt, jpeg, ... • Has Param whose value is a URL –  URL can be file or remote link –  How are these presented •  Code • take set of input events (portfolio) • find what you need and run code • build new event and injects with Jabber/XMPP • All Python and Django
26. skyalert.org Subscription (coming soon) Subscription for YOU or YOUR robot? Talk to me!
27. skyalert.org More Information http://www.eso.org/lists/listinfo/voevent Sign up for VOEvent mailing list http://voeventnet.org/ Events, streams, google http://voevent.org International standards and VO http://skyalert.org/ Almost ready for subscriptions!