German Astrophysical Virtual Observatory

Overview and Results So Far

W. Voges, G. Lemson, H.-M. Adorf

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Now: N x M interfaces

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Future: N + M interfaces

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(GA)VO architecture

Workstation

Registry

Registry Query Interface

VOQL Engine(parsing,splitting,planning)

Portal

WSDL SOAP(Web)Services

MetaDataRepository

DomainModel

Data Access Layer

ResourceModel

MPA

Simulations

Mapping,Services

ROSAT

RASSFields BSC

RASSPhotons

Mapping,Service

SDSS

SQLServer

Mapping,Services

(GA)VO

NGSE

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International Virtual Observatory Alliance

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IVOA working groups

RegistryData Access LayerData ModelingVOQL/ADQLVOTableUCDGrid and Web services

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Standards and Protocols

IVOA exchange standards Simple Cone Search (SCS) Simple Image Access (SIA) Simple Spectra Access (SSA) VOTable OpenSkyNode, VOQL/ADQL

General standards HTTP, XML, SOAP, WSDL

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Registry

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SCS

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Result

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VOTable

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Tools – Aladin

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Data Model

What? Why? ObservationQuantitySimulationDomain model/ontology as “Esparanto”Archive meta-data repositories

«key» -identifier : string

Experiment

Result

-result*

TimeOrderedData

Image

Configuration

-configuration*

InputData

-inputData*

Measurement

ObjectList

VisibilityData

ValueAssignment

Subject

-values

*

-observation

*

Classification

Identification

IVOA::Experiments

«key» -locator : string-description : string

Products::PhysicalArtifact

-subject1

-artifact

1

Protocols::InputDataType

-type 1

Protocols::ConfigurationDescriptor-protocol

1

«key» -identifier : string-documentationURL : string

Protocols::Protocol

-inputDataType

*

-recipe

1

-configurationParameter

1

«key» -identifier : string

Protocols::Objective

-observable

*-observable

*

«key» -name : string-isIndependent : boolean

Protocols::Variable-variable

1

-variables1..*

Values::Quantity-value

1

Values::Classifier-value

1

Values::Identifier-value

1

ConfidenceIndication

-confidence

*

Uncertainty

-uncertainty

1

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GAVO’s Pillars

Federation of datasetsMatching & Classification & Visualization (NGSE)Theoretical VO and Theory-Observation InterfaceGrid computing

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Federation of Datasets

Towards a multi-wavelength view of universeMatching Source extraction (P. Schuecker et al.) Classification (GAVO/ClassX) SED’s

ADQL/OpenSky Node

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Federation of Datasets (cntd.)

Web services Allow J2EE and .NET applications to

interact with each other Based on standards + protocols

HTTP + XML or SOAP + WSDL

Examples MCMCS download manager

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NGSE (Next Generation Search Engine)

Download Manager Retrieves data from multiple distributed

databases

Matcher Matches sources based on sky-position

(astronomical sources have no unique identifier)

Classifier Uses multi-wavelength data for identification

purposes

Visualization Tool

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Theory in the VO

Publication of simulationsExposing theory servicesTheory-observational interface “Virtual telescope”, e.g. for proposal

preparation support

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Grid computing

Working with Globus ToolkitLooking into alternative technologies SGE, EJBs

Gadget simulation running on joint MPE and AIP workstation clustersInterested in a good application that would benefit from parallel distributed

computing: too large to run on a single computer, or require a quick turn around

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GAVO Accomplishments

Publication of ROSAT datasetsDownload ManagerMatcherDocuments ADASS contributions TVO White Paper

WIP VOTable readers and writers Service “adapters”

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ROSAT BSC, FSC & Photons

VO-compatibility: Simple cone search in VOTable out

New features Exposure times Galactic & Cartesian coordinates Healpix indices

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MCMCS Download Manager

Tool … … accesses registry at JHU

User … … selects up to 70 distributed catalogues … specifies one or more sky-locations

Tool … … queries remote catalogues … retrieves datasets (VOTables) for further

processing

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MCMCS Download Manager

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MCMCS Download Manager

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Workflow

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Matcher (on-going work)

Essential for data miningPrototype features

Performs “fuzzy” match between pairs of source lists from different catalogues

Computes probability of real match based on astrometric uncertainties

Moving matcher into production use Currently exported to Canadian Virtual

Observatory Feeding matches to ClassX classifier

Long-term goal: assemble an SED

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Matcher (on-going work)

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Classification (soon)

ClassX: international collaborationRequires data from several large sky-surveys

X-ray: ROSAT (BSC + FSC) Optical: SDSS, USNO Infrared: 2MASS Radio: FIRST, NVSS, SUMSS

True multi-wavelength VO-application

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Theory in the VO

TVO white paperFormation of an IVOA special interest group

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Outlook

Emphasis on 3rd generation REST- or SOAP-based Web

services Proxy/adapter services, e.g. to SDSS, CDS, NED, … “Virtual telescope” for proposal preparation support

4th generation “Grid” application: combination of several Web services into one, e.g. Upload of coordinate list to major datacenters Combine match lists using “fuzzy” matcher Construct quasi SED Feed match candidates into remote ClassX classifier Plan: offer as public service

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Collaboration Models

Listen to scientists/end user requests Support data publicationImplement new services E.g. decision support tool for

(observing or funding) proposal preparation

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How could we help?

Knowledge transfer Publishing datasets in a VO-

compatible form Establishing new services (e.g.

wrappers around legacy code) Offer expertise with Web and J2EE apps,

protocols and new standards

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Questions

What do you expect from us?What role do you see yourself in? Scientist/end user or data provider?

What could you offer?How can we collaborate?

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Discussion