Presentation on theme: "VOEvent NVO Summer School September 2006 Roy Williams NVO.Caltech Alasdair Allen Joshua Bloom Andrew Drake Matthew Graham Rob Seaman Robert White.... and."— Presentation transcript:
VOEvent NVO Summer School September 2006 Roy Williams NVO.Caltech Alasdair Allen Joshua Bloom Andrew Drake Matthew Graham Rob Seaman Robert White.... and many others.... 1604 image of Cas A
VOEvent transport model Publisher Subscriber Author immediate push digest (RSS) resolve query Multiple authors, publishers, subscribers Structured, semantically rich, for machine understanding XML representation Standard transports (web service, email, etc) Standard global identifiers Repository client Aggregator Filter
Caltech Exeter LANL NOAO SDSS SNe U Washington/Stanford Pairitel Berkeley Palomar P60 Caltech Palomar-Quest Caltech Raptor LANL Liverpool Telescope La Palma UKIRT Hawaii Author Publisher Repository Relay Subscriber Faulkes Hawaii/Australia OGLE III Poland GCN NASA/GSFC Microlensing Survey Exeter CTIO/KPNO surveys VOEventNet and eStar
Roles Author Scientific Responsibility Metadata same as IVOA Organization title, shortName, description, logo, contact (Name, Email, Phone), Contributor Publisher XML Responsibility Creates unique IVORN Subscription interface Repository Resolves IVORNs Query interface (SEAP) Relays, Filters, and Brokers Combinations of basic roles
VOEvent Structure Who Publisher, Contact, etc Subscribers will use AuthorIVORN to select WhereWhen (== STC) Can be simple eg RA, Dec, eg UTC 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 Reference Supporting material, eg lightcurve, image
is the scientifically-responsible Author? Rapid Telescope for Optical Response Raptor http://www.raptor.lanl.gov/images/RAPTOR_patchLarge.jpg Robert White email@example.com +1 800 555 1212 ivo://raptor.lanl/organization or An IVORN for an organization Easier for Subscribers to find Author Shorter packet
was actually observed Parser can cast this Group to class phot_pt A time sequence of R- magnitudes
do we think this happened? Tycho's Stella Nova SN Ia 3C 10 supernova remnant Importance of the event observation should I interrupt my telescope schedule? Publisher thinks (prob=0.98) this is a SN1a with given name Possibility this is associated with object 3C10 For draft controlled vocab for concepts see http://www.ivoa.net/twiki/bin/view/IVOA/VOEventVocabulary
STC adopted (No more mealy-mouthed nonsense about RA and Dec elements) pseudocode Let x = WhereWhen/ObsDataLocation/ ObservationLocation/AstroCoords If x[@coord_system_id=FK5-UTC-TOPO] then Let Time = x/Time/TimeInstant/ISOTime Let RA = x/Position2D/Value2/C1 Let Dec = x/Position2D/Value2/C2 < ObsDataLocation xmlns="http://www.ivoa.net/xml/STC/stc-v1.30.xsd" xmlns:xlink="http://www.w3.org/1999/xlink"> 2005-04-15T23:59:59 1.0 148.88821 69.06529 0.03
VO Identifiers Registry finds the VOEvent repository Repository finds the specific event ivo://pq.nvo.caltech/VOEPublisher # 20050523c Publisher IVORN Resolved by registry to find repositories Local ID Not known to registry Created by Publisher Known to event repository delimiter Event IVORN (whole thing)
VOEvent and Registry Author may be registered may be cited by IVORN in VOEvent packet Saves typing Easier for subscriber to pick known authors equivalence of with IVOA Organization Publisher is registered List of authors, How to subscribe Repository is registered Which publishers are kept IVORN resolution. Query interface
Author (science) Publisher (identifier, signature) Repository Registry Usage for VOEvent Client 1.Resolve identifier ivo://publisherID#localID 2. Which repositories have events from this publisher? 3: Send localID 4: Receive event metadata publish event store event VO Global Registry Subscribers
Citation An event can cite another ivo://gcn.nasa/VOEvent#hete_389241a_20050808_230931 Observations can be federated by mutual citation followup observation event collection
Control Author A sends event E to Subscriber S Subscriber software decides on action.... S can followup everything from A S can followup if importance > threshold (importance is part of every event) S can followup if prob(Supernova) > threshhold section has hypothesis, concept, association S can examine the parameters, images, lightcurves section is observations
Transport Querying and web pages as usual client connects to server RSS polling is like this Subscription One of Client keeps open socket to server Server keeps open connection to client (GCN model) Subscriber protocol Jabber/XMPP -- popular IM protocol Home made -- TCP Vanilla Java Messaging One-way SOAP (port 80)
VOEvent Structure Event has ivo:// identifier (the IVORN) Citation Keep it light -- no data in VOEvent-- use links Citation connects events Discovery, Followup, Supercede, Join, Predict Subscription / query / digest (RSS) get only the events you want based on complex criteria based on publisher crossmatch event libraries Transport fabric for human: email, cellphone, IM for robot: IM, web-service, auto-email, socket
Queries for VO Registry Tell me about this Author Tell me about this Publisher Tell me about this Repository Which Publisher has this Author? Which Repository has this Publisher?
http:// VOEventNet.org VOEvents snuffling and snuggling all over the internet.....
Event Synthesis Engine Pairitel Palomar 60 Raptor PQ next-day pipelines catalog Palomar-Quest known Variables known asteroids SDSS 2MASS PQ Event Factory remote archives baseline sky eStar VOEventNet VOEventNet: a Rapid-Response Telescope Grid VOEvent database
Joining VOEventNet VOclient application http://voeventnet.caltech.edu C, Java, or Perl Uses Jabber pubsub jabber server is moriori.cacr.caltech.edu Can publish and subscribe Current event streams: gcnevents (GCN GRB events) estar (OGLE microlensing events lanl (Alternate GCN GRB stream and RAPTOR follow up) sdssss (Sloan Digitial Sky Survey Supernovae)
OGLE Example OGLE III Project (via eSTAR Project) Andrzej Udalski firstname.lastname@example.org 2006-05-28T15:50:24+0000 272.689541666667 -27.7582222222222
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