1. 2005-05-19VOEvent - IVOA Interop Kyoto1 Open Issues for VOEvent Arnold Rots Harvard-Smithsonian CfA / CXC T HE US N ATIONAL V IRTUAL O BSERVATORY

2. 2005-05-19VOEvent - IVOA Interop Kyoto2 The Road Ahead We have a good start on VOEvent, but there are still a number of issues to be resolved – a (i.e., my) selection: –Curation –Content requirements –Data issues –Harvesting and distribution –Services This is a client oriented service

3. 2005-05-19VOEvent - IVOA Interop Kyoto3 Roles There are four distinct roles (aside from Client): –Creator creates VOEvent packet –Publisher assigns ID and makes packet publicly available (push); guarantees continued availability –Repository holds packet and allows retrieval (pull) –Aggregator/broker distribution point (push) Organizations may hold several of these roles

4. 2005-05-19VOEvent - IVOA Interop Kyoto4 Curation Issues Handling of proprietary data Syntax of VO Identifiers for VOEvents Who will provide the repositories? Creators, publishers, aggregators Who is responsible for persistence? Should all data be preserved in perpetuity? What about linked data objects?

5. 2005-05-19VOEvent - IVOA Interop Kyoto5 Content Requirements How much information to include? –The amount of information provided in a VOEvent object should be designed to satisfy the needs of the users, not what the creator thinks the users need –But how much is enough? –Coordinate transformations should be facilitated (STC!)

6. 2005-05-19VOEvent - IVOA Interop Kyoto6 STC Requirements The requirement for Space-Time Coordinate metadata is that they: –provide sufficient and necessary information –are self-consistent For an observation two sets of metadata are required: –Location of the observatory –Location that the observation pertains to

7. 2005-05-19VOEvent - IVOA Interop Kyoto7 Data Issues How to characterize sensitivity adequately? How to handle and administer linked data objects? Classification of events; an event ontology? How to express hypotheses in an accurate as well as meaningful manner? How to adequately express a series of events?

8. 2005-05-19VOEvent - IVOA Interop Kyoto8 Harvesting and Distribution Trusted contributors? Or a free-for-all? Authentication? contributors, clients? Broadcasting versus querying; broker services Subscription parameters: keeping the volume down Estimated volume

9. 2005-05-19VOEvent - IVOA Interop Kyoto9 Services Auxiliary services –Databases of known objects - moving objects, transients, etc. –Name resolvers Query services –Sophistication of queries (e.g., asteroids with a > 15 au)