Transcript gerard schneider

Theory in the
Virtual Observatory
Gerard Lemson, GAVO
The VO
 Broad goal
 Make results of astronomical research, data and applications, more readily
available to larger community, and create value-adding services.
 Facilitate:
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communication of results
checking of results
use of results
comparison of different results
combination of different results to create new ones
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online availability of datasets and applications
standardized publication and discovery mechanisms
standardized description (meta-data, FITS++)
standardized selection mechanisms
standardized form(at)s of transmitted data
value added services
 Through
 Why ?
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Ringberg, Gerard Lemson
FIRST
ROSAT
2MASS
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GAIA
SDSS
Ringberg, Gerard Lemson
FIRST
ROSAT
2MASS
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GAIA
SDSS
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 Registry
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 publication
 discovery
Data models
 description (UCD)
Query protocols
 selection (cone search, ADQL)
 combination (XMatch)
Data access protocols
 retrieval (VOTable)
Applications
 user interfaces (Aladin)
 visualisation (VOPlot)
 analysis (…)
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Theory
 Existing protocols not applicable
 Position based queries
 Combination of different archives less obvious
 Data models insufficient
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New “observables”
Different “provenance”
Different characterization
More complex data structures
 Less well developed history of archiving
 No FITS for simulations
 New use cases
 Theorists : data mining simulation results
 Observers : virtual telescope
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Ringberg, Gerard Lemson
Archiving of simulations
 Use relational database
 GalICS
 SDSS
 Halo merger trees from milli-Millennium
 data model for trees
 SAM galaxy catalogues
 links to halos
 add merger trees
 SQL query interface
 http://www.g-vo.org/mpasims (Springel, Croton, Blaizot)
 Soon: add dynamic SAM to interface
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Observed
Virtual Telescope
Simulated
Thanks to Volker Springel
Thanks to Alexis Finoguenov, Ulrich Briel,
Peter 2005-06-30
Schuecker, MPE)
Ringberg, Gerard Lemson
Virtual Telescope
 Use simulations for help in interpreting
observations (e.g. Peter Schneider for this
morning)
 Bring simulations into “observational plane”
 Create results similar to observations
 Can be analysed with same techniques as
observations
 Can be compared “directly” to obs-s\
 Use cases:
 Check observational biases using realistic models
 Survey/observation planning
 Check models to observations
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Ringberg, Gerard Lemson
Prototypes
 Visualisation
 Smac (Dolag)
 MoMaF (Blaizot)
 Virtual telescope
 http://www.g-vo.org/planck
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Interoperability:
Virtual telescope configuration
 Components
 simulations
 telescope models
 foregrounds (incl. lensing)
 Specification
 “pre-observation image”
 interfaces
 workflow
 Implementations …
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Virtual telescope
data flow
X-Ray
Observation
“Find similar
simulations”
Theory/
observational
interface
Extract queriable
features (dm, ucd)
Feature Extractor
Retrieve telescope
configuration (dm)
Retrieve data (dal)
Virtual telescope
Observe selected
simulations virtually
(application, services)
Registry service
Simulation archive
Compare
Retrieve data (dal)
Comparator
Analyse
Analysis softawre
Find possibly relevant
hydro simulations
(registry, dm, voql)
Quotes:
 "I think the global virtual observatory is a
fantastic idea"
- Martin Rees, Physics Today, Feb 2002
 ... too much money will be sunk into software; ...
archives at ground-based observatories should
be brought up to snuff before thinking about
linking them; and ... users won't be able to trust
the processed data they call up.“
- Physics Today, Feb 2002
 “… that VO nonsense …”
- anon, Ringberg 2005
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Discussion
 What do you want from the VO ?
 What should VO projects focus on ?
 What could/do you contribute to the VO ?
 Why is the VO a waste of resources ?
 Should spend money on more postdocs.
 What are the dangers of the VO?
 Too easy to do to bad science.
 What are the possible advantages of the VO?
 Easier to do good, new science.
 Easy to check bad science.
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