Demonstration of VO Tools and Technology

Tamás Budavári Johns Hopkins University

9/13/2004 NVO Summer School, Aspen 2004

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VO Tools

Direct access toImagesSpectraCatalogs

Higher levelCross matchetc.

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SDSS Image Cutout

Build JPEG mosaicsFor given (RA, Dec)Arbitrary zoom levelsOverplot catalog dataOverplot geometryMapQuest like navigationList of objects

Web servicesJPEG returned in DIMEor byte array in XML Kudos to Maria

Nieto-Santisteban

Kudos to Maria Nieto-

Santisteban

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Spectrum Services

Public repository500,000 spectra (2B row)

Spatial search and more

Register & submit yours

Web siteOn-the-fly plotting

Building composites

Web servicesMore options and tools

Kudos to László Dobos

Kudos to László Dobos

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Bandpass Services

Public repositorySearch by keyword or eff

Extract in various formatsRegister & submit yours

Web siteOn-the-fly plottingEasy access to all

Web servicesTo code against

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Catalog AccessU wanna talk database?

Structured Query Languageor SQL for short (standard)

Simple syntaxSELECTSELECT <columns> FROMFROM <table> WHEREWHERE <conditions>

For example: select ra, dec

from galaxy where r<19

What else do we need?

To specify area on sky• Could be very complicated

Standard interface to DBs

• XML Web Services for interop

Tools to federate archives

• Dynamically for flexibilityAstronomical Data Astronomical Data Query LanguageQuery Language

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Open SkyQuery

SkyNode interface to archives

Implements ADQL returns VOTableBasic node understands “REGION”Full node understands “XMATCH”

SkyQuery portalKnows the SkyNodes from RegistryUnderstands federated query

http://openskyquery.net

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Summary

Direct access toImagesSpectraCatalogs

Higher levelCross matchetc.

Your project

Your project

herehereYour project

Your project

herehere

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Project IdeasAverage QSO spectrum?

Composite spectrum of the 20 most distant SDSS quasars?Average spectrum as a function of redshift?

• Try a few redshift bins by hand this afternoon (pick ~10-20 objects for each bin)• Write code to analyze many more redshift bins (flat z histogram inside bin?)

Favorite object?Get image, spectrum and/or catalog data for your pet galaxy

• Don’t remember the coords? Try name resolver at http://voservices.net/ned/

Build a series of SDSS mosaic images • Get images of astronomical objects given by RA and Dec (or by name?)• Write code to make a movie zooming on any given galaxy (coords or name)

Your idea here…

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Where to go

Links in the talkhttp://skyserver.sdss.org/http://voservices.net/spectrum/http://voservices.net/filter/ http://openskyquery.net/

Other relevant linkshttp://us-vo.org/http://voservices.org/http://www.ivoa.net/