VOEvent An Information Infrastructure for Immediate Astronomical Events Roy Williams NVO co-director

IVOA working group VOEvent Define semantics of message –Draft document for discussion –Curation, Wherewhen, How, What, Hypothesis Start vocabulary –Based on UCD -- IVOA standard Work with Strasbourg experts Use existing schema where possible –IVOA, RTML, STC Buy-in from communities –GRB/Swift, RTML, LIGO, Raptor, –LSST, Palomar-Quest, PanStarrs, –etc etc

Current systems Partial List IAU telegrams Gamma-ray Coordinate Network Astronomer's telegram Global Microlensing Array Network ???? Text-based meaning human-based -based all messages to all subscribers

Proposed system Curation from IVOA curation schema, from Dublin Core When, Where STC? Simple? How instrument state –different schema for different instruments –RTML What exactly what was seen –different schema for different instruments Hypothesis probability list of: –supernova, comet, asteroid,..... –how can we make this list?

Proposed system Event has ivo:// identifier Citation Keep it light -- no data in VOEvent-- use links Subscription/query get only the events you want –based on complex criteria crossmatch event libraries Transport fabric for human: , cellphone for robot: web-service, auto-

VOEvent: General Info Who is making this report? –From VORegistry Based on Dublin Core

Dublin Core Title: A name given to the resource. Creator: An entity primarily responsible for making the content of the resource. Subject: A topic of the content of the resource. Description: An account of the content of the resource. Publisher: An entity responsible for making the resource available Contributor: An entity responsible for making contributions to the content of the resource. Date: A date of an event in the lifecycle of the resource. Type:The nature or genre of the content of the resource. Format: The physical or digital manifestation of the resource. Identifier: An unambiguous reference to the resource within a given context. Source: A Reference to a resource from which the present resource is derived. Language: A language of the intellectual content of the resource. Relation: A reference to a related resource. Coverage: The extent or scope of the content of the resource. Rights: Information about rights held in and over the resource.

VOEvent: Where and When Where in the sky and when? –Simple: RA, Dec in J Julian Day –Not good enough for precise positions –Sophisticated How to ease burden of interpretation Space-Time Coordinates –Where was the observer? –What about nutation? –What about surface of Mars?

VOEvent: How How was the event detected? –Instrument description: which is in there? Used Gunn R filter Used MySpecial filter Camera darks and flats files at Dome didnt open until 3am –Instrument-specific for accurate info

VOEvent: What was detected? Instrument independent –Magnitude increase –GW strain –Good candidate for UCD eg phot.color.Gunn (Color index in Gunn system) Instrument dependent –Mag increase in MyFilter –Trigger number 736 with SNR=6

VOEvent: Classification What do we think happened? –How to build ontology?

Event Vocabulary Astronomers telegram –Radio, Millimeter, Sub-Millimeter, Far-Infra-Red, Infra-Red, Optical, Ultra-Violet, X-ray, Gamma Ray, >GeV –Request for Observations, A Comment, –AGN, Asteroids, Binaries, Black Holes, Comets, Cosmic Rays, Cataclysmic Variables, Globular Clusters, Gamma-Ray Bursts, Meteors, Microlensing Events, Neutron Stars, Novae, Planets, Planets (minor), Pulsars, Quasars, Soft Gamma-ray Repeaters, Solar System Objects, The Sun, Supernovae, Supernova Remnants, Transients, Variables, Stars UCD –IR, UV, X-ray, gamma, mm, opt, radio –Each in categories em.line.Brgamma Bracket gamma line em.UV nm Ultraviolet between 100 and 200 nm em.X-ray.soft Soft X-ray IAU Telegram –Outbursts Of Unusual Variable Stars, Features On Planetary Surfaces

Unified Content Descriptors UCD is a semantic type src.orbital.eccentricityOrbit eccentricity meta.code.mimeMIME type pos.gal.lonLongitude in galactic coordinates phys.at.crossSectionAtomic cross-section Can be resolved by web service –to description, examples, etc

VORegistry as a model for VOEvent?

Registry model VOEvent registry user alerter publish subscribe get ID user query

Registry model VOEvent registry VOEvent registry VOEvent registry user alerter publish harvest subscribe user query

Distributed Registry Caltech NCSA STScI/JHU HEASARC Astrogrid CDS JapanVO Registries as of Jan 05 ESO CfA NOAO

VO Registry VOResource Schemas and instances VOIdentifier ivo://nvo.caltech/DPOSS#f123 Subscribe service registry Extension schemas Harvest Publish service registry Human via web form Machine via web service Query service

VO Identifiers ivo://mydomain.com / mySkySurvey # file00037.fits Authority ID Registered with IVOA Resolved by registry Resource ID Created by Authority Resolved by registry Record ID Not known to registry delimiter