National Astronomy Meeting 5th April 2006

The X-Ray Synoptic Viewer:

X-Ray Data Access and Reductionin the Virtual Observatory

Duncan Law-Green (LEDAS: Leicester Database & Archive Service)

LEDAS homepagewww.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.

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 systemXrayDSA: 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.

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?

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

X-Ray Synoptic Viewer - 2

ALADIN image here

Raw & processed archive data

FITS HDS JPG

X-Ray Synoptic Viewer - 2

ALADIN image here

Raw & processed archive data

Catalogue Fluxes

FITS HDS JPG

X-Ray Synoptic Viewer - 2

ALADIN image here

Raw & processed archive data

Catalogue Fluxes

Generated Fluxes

FITS HDS JPG

X-Ray Synoptic Viewer - 2

ALADIN image here

Raw & processed archive data

Catalogue Fluxes

Generated Fluxes

Flux limits

FITS HDS JPG

X-Ray Synoptic Viewer - 2

ALADIN image here

Raw & processed archive data

Catalogue Fluxes

Generated Fluxes

Flux limits

Automation (workflow)

Generated spectra/time series

FITS HDS JPG

Mission archives for Synoptic Viewer

Instrument Operational datesEinstein IPC/HRI 1978-1981EXOSAT CMA 1983-1986ROSAT PSPC/HRI 1990-1999ASCA SIS/GIS 1993-2001SAX LECS/MECS 1996-2002Chandra ACIS/HRC 1999-Chandra LEG/MEG 1999-XMM-Newton EPIC 1999-XMM-Newton RGS (grating) 1999-Swift XRT 2004-Suzaku XIS 2005-

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. fx / fopt

or optical colours. Account for X-ray pointing

Rank by figure-of-merit, give statistical confidence.

S1 S2

S3

S4

Science Cases...

Synoptic Viewer

Multi-mission historical X-ray light curves.Long-term variability of all sources in a nearby galaxy. Search formost 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, >105 sources) with optical, IR. Figure-of-merit provides large, “clean” samples of sources.

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