Gerard Lemson Theory in the VO and the SimDB specification Euro-VO DCA workshop Garching, June 26, 2008 Feedback questionnaire

Gerard Lemson Overview Theory in the VO Definition Motivation Issues Standardisation for theory Existing standards Theory interest group: SimDB and SimDAP Prototype implementations

Gerard Lemson What theory? Simulation resultss raw, “Level-0” data Post-processing, Level-1 products halo catalogues theoretical spectra... Synthetic observations (Level 2) virtual telescope Analysis (Level 3?) correlation functions power spectra... Services related to these This talk, focus on LARGE simulations and post-processing products 3+1D, spatial/temporal “micro-physics” simulations under discussion, sometimes already supported.

Gerard Lemson Detailed observations electron density gas pressure gas temperature Courtesy Alexis Finoguenov, Ulrich Briel, Peter Schuecker, (MPE)

Gerard Lemson Require detailed models Courtesy Volker Springel

Gerard Lemson Observations in the VO Most VO efforts concentrate on observational data sets simple observables: photons detected at a certain time from a certain area on the sky long history of archiving pre-existing standards (FITS) valuable over long time (digitising >80 yr old plates) Standards observationally biased common sky: cone search, SIAP, region common objects: XMatch data models: characterisation of sky/time/energy, STC

Gerard Lemson Theory in the VO: issues Simulations not so simple Complex observables, non-standard No standardisation on data formats or metadata Archiving ad hoc, for local use Moore’s law makes useful lifetime relatively short: few years later can do better Current IVOA standards somewhat irrelevant No common sky No common objects New data models required for content, physics, code

Gerard Lemson “Moore’s law” for N-body simulations Courtesy Simon White Millennium Run Mare Nostrum

Gerard Lemson Historical simulations Toomre & Toomre, 1972 Di Matteo, Springel and Hernquist, 2005 Volker Springel

Gerard Lemson Theory in the VO: issues Simulations not so simple Complex observables, non-standard No standardisation on data formats or metadata Archiving ad hoc, for local use Moore’s law makes useful lifetime relatively short: few years later can do better Current IVOA standards somewhat irrelevant No common sky No common objects New data models required for content, physics, code

Gerard Lemson So why bother? Simulations are interesting: For many cases only way to see processes in action Complex observations require sophisticated models for interpretation Bridging gap in specialisations: not everyone has required expertise to create simulations, though they can analyse them. Many use cases do not require the latest/greatest exposure time calculator survey design

Gerard Lemson DAL standards Similarity of products SSAP theory spectra SCS-like mock catalogues SIAP-like visualisation services

Gerard Lemson Other Registry Allows any web service ADQL + TAP theory SkyNode (Rick Wagner) Millennium Run (see later today) Applications VisIVO (see later today) Semantics theory UCDs Vocabularies/ontologies for astronomical objects, physical processes,...

Gerard Lemson SimDB and SimDAP Effort of IVOA theory interest group Originally attempt at S*AP protocol for simulations (SNAP) queryData getData DAL v2: based on data model. queryData in terms of elements in DM getData special attention large datasets no uniform formats see SimDAP presentation (Claudio Gheller)

Gerard Lemson SimDB: Simulation Database Supports discovery of interesting simulation results. and links to (SimDAP)services for accessing them Rich data model describing simulations and post-processing products Focused on 3+1D simulations but easily extended

Gerard Lemson Common questions What was simulated? LSS, galaxy merger, rings of Saturn What physics was included? gravity only, hydrodynamics, chemistry How is the world represented? N bodies, adaptive mesh, spherically symmetric 1D What properties are calculated? position, velocity, mass, temperature, density, chemical abundances How do I get access? etc.

Gerard Lemson SimDB: Data model (in progress)Data model

Gerard Lemson File

Gerard Lemson Storage

Gerard Lemson Results of Experiments

Gerard Lemson Experiments

Gerard Lemson Protocol

Gerard Lemson Parameters

Gerard Lemson Target

Gerard Lemson Web service

Gerard Lemson SimDB data modeldata model

Gerard Lemson Complex? Registry data model Spectrum Data Model STC SDSS SkyServer etc.

Gerard Lemson Representations (Generated)* XML Schemas Protocol: PDR code (courtesy Franck LePetit + Laurent Bourges) Simulation: Millennium Run Ideally generated from simulation and post-processing pipe-lines Relational Database Schema Java code HTML *

Gerard Lemson XML fragments (PDR protocol)

Gerard Lemson Representations (Generated)* XML Schemas Protocol: PDR code (courtesy Franck LePetit + Laurent Bourges) Simulation: Millennium Run Ideally generated from simulation and post-processing pipe-lines Relational Database Schema Java code HTML *

Gerard Lemson RDB views (ADQL/TAP interface)

Gerard Lemson RDB tables (generated)

Gerard Lemson Representations (Generated)* XML Schemas Protocol: PDR code (courtesy Franck LePetit + Laurent Bourges) Simulation: Millennium Run Ideally generated from simulation and post-processing pipe-lines Relational Database Schema Java code HTML *

Gerard Lemson SimDB: Implementation Complex data model requires more advanced support Simple HTTP requests insufficient Browsing or full query language needed More registry than S*AP queryData a few central sites (France, Germany, Italy, USA) with advanced access methods

Gerard Lemson (Laurent Bourges)

Gerard Lemson Access Services (in progress) ADQL+TAP relational mapping global-as-view wrapping “REST” XML documents GET and PUT (and DELETE ?) OAI ala Resource Registry harvesting Web Browsing (example)example Fully generated support possible (in progress)

Gerard Lemson Prototypes CNRS GalMER ITVO Trieste: Catania: Under development SimCat (UCSD) PDR/SimDB (Paris) Horizon/GalICS (Lyon) GAVO (hydro simulations)

Gerard Lemson Main message SimDB/SimDAP in progress Participate in the IVOA theory interest group If you have a “theory service” whether standard or not: wrap it deploy it register it

Gerard Lemson Thank you. Thanks to Ugo Becciani Laurent Bourges Igor Chillingarian Claudio Gheller Norman Gray Franck LePetit Mireille Louys Patrizia Manzato Rick Wagner Hervé Wozniak