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ADASS, London Sep 23-26, 2007 VOExplorer : Visualising Data Discovery in the Virtual Observatory Jonathan Tedds University of Leicester/AstroGrid/ EuroVO DCA science team jat@star.le.ac.uk
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Jonathan Tedds http://www.astrogrid.org – see our demo stand upstairshttp://www.astrogrid.org VO Explorer: Noel Winstanley + Andy Lawrence & AstroGrid science team
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Jonathan Tedds VO Explorer: beta release ~Nov 07 AstroGrid front end, part of VOdesktop Resource-centric Select a search-space Search for resources Filter these resources View selected resources Use the selection –Invoke it –Save/Bookmark/Tag it –Export it
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Jonathan Tedds Access existing X-ray cluster catalogues Browse through keyword metadata
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Jonathan Tedds Find
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Jonathan Tedds Resources!
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Jonathan Tedds Euro-VO: –Technical System with –Content + Resources and –Operations + Support Science driven –VO Technology Centre –VO Facility Centre –VO Data Centre Alliance Euro-VO Science advised via Euro-VO Science Advisory Group content + resources technical system operations + support
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Jonathan Tedds If data in a simple DB can publish to VO in ~day! As demonstrated at June07 EuroVO DCA workshop at ESAC For catalogues, images,spectra & transient events transient events content + resources technical system operations + support
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Jonathan Tedds Description
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Jonathan Tedds Filter
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Jonathan Tedds Query on position
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Explore by position: AstroScope
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Jonathan Tedds Plastic/SAMP – visualise selected data
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Jonathan TeddsEnabling VO Science HelioScope displays the results of time queries submitted to Simple Time Access Protocol (STAP) web services – E.Auden, S.Dalla + VOevent (e.g. A.Allan) STAP specification: http://wiki.astrogrid.org/bin/view/Astrogrid/SimpleTimeAccessProtocol STAP query parameters: Start / stop datetimes (mandatory) Data format (mandatory) Instrument ID Time resolution Data ID of individual data products Position RA & Dec (for astronomical events) Size of search box around position RA & Dec Band – wavelength range
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Jonathan Tedds Access all extended 2XMM X-ray sources Make own X-ray cluster candidate catalogue Filter large multiwavelength archives remotely: –Create manageable science subsets
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Jonathan TeddsEnabling VO Science 247K detections 192K unique sources –520 sq.deg. / 330 sq.degs excluding overlap –Full catalogue product set available –World’s largest ever X-ray catalogue – see poster by C.Page et al. Just Out (Aug07): THE 2XMM CATALOGUE
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Jonathan Tedds Find
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Jonathan Tedds Columns
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Jonathan Tedds Filter columns
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Jonathan Tedds Use
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Jonathan Tedds Query
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Jonathan Tedds Help!
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Jonathan Tedds Save as format
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Jonathan Tedds Save results
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Jonathan TeddsEnabling VO Science Correlation with SDSS Select SDSS galaxies within 1 arcmin of 411 X-ray positions –photometry (ugriz), photometric redshifts –spectra, spectroscopic redshifts –colour thumbnail images Visual inspection of images, spectroscopic and photoscopic redshifts
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Workflows – see E.Gonzalez-Solares talk Python, Perl, IDL scripts Single archive image search Cone search for multiple, user defined archives Sextractor script – generate catalogue from images Montage - mosaic tool Taverna Graphical interface Embed existing code (any language)
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Workflows – see E.Gonzalez-Solares talk Python, Perl, IDL scripts Single archive image search Cone search for multiple, user defined archives Sextractor script – generate catalogue from images Montage - mosaic tool Taverna Graphical interface Embed existing code (any language)
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Workflows – see E.Gonzalez-Solares talk Python, Perl, IDL scripts Single archive image search Cone search for multiple, user defined archives Sextractor script – generate catalogue from images Montage - mosaic tool Taverna Graphical interface Embed existing code (any language)
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Jonathan TeddsEnabling VO Science Correlation with SDSS Spectroscopic z = 0.223 (Lamer+, in prep)
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Jonathan Tedds AstroGrid front end, part of VOdesktop Resource-centric Select a search-space Search for resources Filter these resources View selected resources Use the selection –Invoke it –Save/Bookmark/Tag it –Export it http://www.astrogrid.org – see our demo stand upstairshttp://www.astrogrid.org
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Jonathan Tedds Better stop…!
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Jonathan Tedds AstroGrid Redshift Maker
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Jonathan Tedds SDSS DR5 optical sources associated with 2XMMp candidate clusters Total extended sources: 6271 Selections: –offax > 4 arcmin, all EPIC full frame –abs (bII) > 20o, ext_ml > 5 Remaining: 2136 In SDSS DR5 footprint: 867 Unique: 569 After visual screening: 411
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Jonathan Tedds Advantages of VO data access Accessing multiwavelength data easier: –Do not need to access different interfaces, register once only
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Jonathan Tedds
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Advantages of VO data access Accessing multiwavelength data easier: –Do not need to access different interfaces, register –Data access from one single entry point –Able to build workflows i.e. pieces of code which run on the server and are reusable
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Jonathan Tedds Advantages of VO data access Accessing multiwavelength data easier: –Do not need to access different interfaces, register –Data access from one single entry point –Able to build workflows i.e. pieces of code which run on the server and are reusable Tools to analyse the returned data –Different tools which share standards on how to interoperate
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Jonathan Tedds Command Line Scripting Python script to cross match 2XMMp cluster candidates with SDSS DR5 using STILTS library
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Jonathan Tedds Command Line Scripting Return VOTable of SDSS DR5 sources within given radius for each input cluster position
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Jonathan Tedds Command Line Scripting
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Jonathan Tedds Command Line Scripting
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Data exploration & visualisation
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Jonathan TeddsEnabling VO Science Publishing VOEvent Data (e.g. A.Allan) First point of VG –Subpoint 1 –Subpoint 2 Sub sub point 2.1 Second point of VG –Etc…
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Jonathan TeddsEnabling VO Science X-ray luminosities
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Jonathan Tedds Data Centre census - archives Separate information on archives from information about data/products Archives – –Total volume of holdings (GB) – –Total number of astronomical objects, number of database rows and columns – –Contact point and scientific contact point Uniqueness of the data - is the same data hosted elsewhere? Public/Proprietary nature Completely open / Data public after proprietary period / Access restricted Human resources supporting the archive History and expected lifetime of the archive Number of users of the archive Level of VO awareness current compliance with VO standards? intent to utilize VO standards? is VO compliance required by the archive governing bodies?
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Jonathan Tedds Data Centre census – data type
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Jonathan Tedds Data Centre census – theory, tools Theory data centres – –Distinguish theoretical model archives and services that provide computational capabilities – –General scientific area, e.g. Stellar models / Cosmological / Galaxy formation /..journal keywords? – –For archives of pre-computed models collect the same information as for observational archive (where applicable) – –Theory services What is the current interface: web interface / standalone tools / command line /other Typical computation time (seconds/hours/days) Intent to use some kind of distributed or GRID computing – –Theory data products (general types – e.g. 6-d N-body cubes, spectral, images, ??) Tools and software suites – –Are the tools applicable to: images / spectra / multi-d data /interferometry / catalogues / models / accessing other services – –Tool interface: stand alone tools / web interface / command line / software environment / other ? – –Level of VO awareness Current compliance with VO standards Intent to utilize VO standards
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Jonathan TeddsEnabling VO Science A STAP query result is a VOTable describing each data product that matches the time range and other constraints, including Solar images Solar time series Astronomical and solar VOEvents The AstroGrid implementation of STAP requires the service provider to include each matching data product’s start and end time, access URL, and minimal curation metadata. Service providers can also specify additional database columns to include in the VOTable. Solar and STP STAP services: TRACE SOHO EIT, CDS, MDI, LASCO Wind Madrigal ACE RHESSI Mauna Loa Solar Observatory (late 2007) Polar Cluster Ulysses NOAA GOES x-ray flares SOHO-LASCO coronal mass ejections BATSE x-ray flares Solar Dynamics Observatory (2009)
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Jonathan Tedds 2XMMp catalogue of X-ray sources 2XMMp : all sky map 2XMM: new serendipitous X-ray source catalogue from XMM –EPIC public observations Feb 2000 – April 2006 2XMMp: pre-release of 2XMM released July 2006 –Filtered subset by field quality Largest X-ray catalogue ever –150K detections from 2400 observations ~ 117K unique point sources ~ 5K unique extended sources –400 sq.deg. (~280 sq deg overlap corrected)
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