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National Astronomy Meeting 5 th April 2006 The X-Ray Synoptic Viewer: X-Ray Data Access and Reduction in the Virtual Observatory Duncan Law-Green (LEDAS: Leicester Database & Archive Service)
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LEDAS homepage www.ledas.ac.uk What is LEDAS? UK’s high-energy astrophysics data centre, located at Leicester In continuous operation since 1989 (EXOSAT database). Current data holdings >1.6TB processed and calibrated bulk data from several major X-ray astronomy satellites (Einstein, EXOSAT, ROSAT, Ginga, ASCA, XMM-Newton, Chandra). Access to >420 astronomical catalogues and science reference data (e.g. spectral line lists) Database search and display facilities developed in- house (ARNIE5) DBMS: HEASARC Browse (legacy), TDB binary, Sybase (Chandra mirror), MySQL, Postgres. Successful, attracting >250,000 hits/month in 2005, c.f. 2 million hits/month for SDSS SkyServer.
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AstroGrid Deployment @ LEDAS : 1 Mar 04: New server “Galahad” (AG/LEDAS) (Dual Xeon 2.6, 2GB RAM, 1TB RAID) Jul 04:AG Itn 05: Local MySQL server on galahad. Successful test PAL deployment (HEASARC Master Optical, ~4 million rows) Feb 05: Leicester AG staff begin using Galahad for v1.0 release work. v1.0 components installed on Galahad: Registry, XrayDSA, FileStore, JES. Registry: fully operational, core AG system XrayDSA: Deployment of 1XMM catalogue via MySQL Dec 05:Disk failure on galahad, loss of XrayDSA, partial loss of FileStore. Rebuild in progress. Jan 06:New server “Camelot” (LEDAS) (Dual Opteron, 2GB RAM, 1.2TB RAID) Mar 06:Deployment of DSA v1.1, local Registry on camelot.Work in progress.
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AstroGrid Deployment @ LEDAS : 2 Future Developments: DSA for all 420+ catalogues at LEDAS Bulk data: SIAP (images), SSAP (spectra), “STAP” (time series?) Complex, heterogeneous datasets X-ray Data Model Local LEDAS Registry (already running) MySpace server Community for high-energy researchers High-energy science workflows External Resources: VO support for Swift UKDC (catalogues already in LEDAS) VO support for WASP archive @ Leicester?
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Synoptic: “Of or constituting a synopsis; presenting a summary of the principal parts or a general view of the whole.” (dictionary.com) X-Ray Synoptic Viewer (XSV): An integrated graphical VO tool for: ● viewing X-ray images from multiple missions ● selecting X-ray datasets for further inspection ● extracting calibrated flux information ● further processing of archive data fluxes/limits ● Historical X-ray light curves ●...more
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X-Ray Synoptic Viewer - 2 ALADIN image here Raw & processed archive data FITSHDSJPG
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X-Ray Synoptic Viewer - 2 ALADIN image here Raw & processed archive data Catalogue Fluxes FITSHDSJPG
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X-Ray Synoptic Viewer - 2 ALADIN image here Raw & processed archive data Catalogue Fluxes Generated Fluxes FITSHDSJPG
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X-Ray Synoptic Viewer - 2 ALADIN image here Raw & processed archive data Catalogue Fluxes Generated Fluxes Flux limits FITSHDSJPG
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X-Ray Synoptic Viewer - 2 ALADIN image here Raw & processed archive data Catalogue Fluxes Generated Fluxes Flux limits Automation (workflow) Generated spectra/time series FITSHDSJPG
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Mission archives for Synoptic Viewer InstrumentOperational dates Einstein IPC/HRI1978-1981 EXOSAT CMA1983-1986 ROSAT PSPC/HRI1990-1999 ASCA SIS/GIS1993-2001 SAX LECS/MECS1996-2002 Chandra ACIS/HRC1999- Chandra LEG/MEG1999- XMM-Newton EPIC1999- XMM-Newton RGS (grating)1999- Swift XRT2004- Suzaku XIS2005-
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X-Ray Correlator (XCO) Cross-correlation tool, integrated with Synoptic Viewer. Cross-match X-ray source positions (from LEDAS images or source catalogues) with external databases. More challenging at X-rays because of positional uncertainties: 10”-30” for earlier missions, to 1”-5” for XMM-Newton, results in multiple counterparts. User-selectable figure-of-merit, match algorithm Apply matching constraints by e.g. f x / f opt or optical colours. Account for X-ray pointing Rank by figure-of-merit, give statistical confidence. S1S2 S3 S4
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Science Cases... Synoptic Viewer Multi-mission historical X-ray light curves. Long-term variability of all sources in a nearby galaxy. Search for most variable sources in entire sky, e.g. Stellar capture events in nuclei of nearby galaxies, many orders of magnitude flux variation on t ~ months-years. Applicability at other wavebands (e.g. WASP). X-Ray Correlator GRB identifications: integrated, efficient identification of counterparts, quantitative basis for ID. Need confidence in ID for rapid followup observations. XMM identifications: federation of large X-ray catalogues (e.g. 2XMM, >10 5 sources) with optical, IR. Figure-of-merit provides large, “clean” samples of sources.
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Project status: PPARC 2005 data curation review: expressed support for UK data centres Bid submitted Dec 2005, awaiting response....watch this space! http://www.ledas.ac.uk/ Leicester Database & Archive Service ledas-help@star.le.ac.uk
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