Australian Virtual Observatory

International Astronomical Union GA 2003Joint Discussion 08

17th-18th July 2003 Sydney

David BarnesThe University of Melbourne

Our take on virtual observatories

• bring legacy astronomy archives on-line and ensure future project compliance

• provide access to archived realisations of simulations and to resources for computing against new parameter sets

• describe data fully, and support a small and well-chosen set of interoperability protocols

• develop tools and interfaces to find, acquire, process and visualisevisualise data

• build national and international grids to host the data, tools and interfaces

Why we’re involved…

• Australian data archives are under-utilised, internationally and nationally.

• Common format data enables common tools: “learn once, use many”. Tools can be cross-wavelength, cross-paradigm (observed, simulated, …)

• It is a fair bet that VOs of some sort will be with us for some time, so we need to start learning about VO techniques in Australia.

• It is simply a Good Thing to do things The Same Way, where possible.

• We have expertise to offer in niche areas, eg. WCS, visualisation, spectral line surveys, …

Aus-VO structure 2003• Phase A funded AUD 260K by a 2003 Australian

Research Council grant:– The University of Melbourne– The University of Sydney– CSIRO Australia Telescope National Facility– Anglo-Australian Observatory

• Additional institutes participating w/o direct funding from the ARC grant:– ANU, Mount Stromlo Observatory & APAC– CSIRO Mathematical and Information Sciences– University of Queensland– VPAC & GridBus (Melb)

• Lead investigator Rachel Webster (Melb)• Project scientist David Barnes (Melb)

Aus-VO projects 2003

• Common format on-line archive projects:– HIPASS catalog: HI Parkes All Sky Survey: neutral

Hydrogen spectral line survey, 4,300 sources with ~30 parameters and 1024-channel spectra

– SUMSS catalog: Sydney University Molonglo Sky Survey: radio continuum survey at 843 MHz, 107,000 sources with ~15 parameters

– 2dFGRS QSO catalog: 2-degree Field Galaxy Redshift Survey: optical spectra of >20,000 southern quasi-stellar objects

– ATCA archive: Australia Telescope Compact Array archive: all observations since 1988, circa 1.5 TB of more than 1,000 separate observing projects! Substantial exercise in describing data with metadata.

– MACHO archive: Massive Compact Halo Objects archive: 8yr lightcurves for >18M stars

Aus-VO projects 2003• Server-based visualisation tools:

– client canvas for legacy software package AIPS++ to display to from a remote server (ATNF)

– grid-service implementation of distributed volume rendering - remote data transferred to remote cluster, with display and control applet supplied by coordinating portal

• Pipelines to enable on-line reprocessing of archived raw or pre-processed telescope data:– Molonglo Observatory Synthesis Telescope– ATCA archive thumbnail generator

Niche role: visualisation• ATNF will build a web-

based PixelCanvas so that AIPS++ visualisation apps can be deployed as Web-Service and Grid- Service Java Applets

• AIPS++ is modern, OpenSource software for reducing (radio) astronomy data, 1.6M lines of code.

Collaborative role: grid-based volume rendering

• With AstroGrid we have developed our existing distributed-data volume rendering code into a fully-fledged Grid-Service. [see [see the interactive demo at the IVOA stand of the Expo] the interactive demo at the IVOA stand of the Expo]

• render lines of sight through the entire volume - this is volume renderingvolume rendering and may offer new insights to complex data collections, images and catalogs.

Team effort!• Collaborating groups now include

– Melbourne (Physics & CSSE Gridbus)– AstroGrid (Cambridge, Leicester)– VPAC, APAC, CSIRO CMIS, Jodrell Bank

Observatory, Univ QLD, as data centres and rendering clusters

• Why?– Saves you from fetching large data files– Enables use of distributed computing resources– Demonstrator of grid technologies for VOs

General future challenges & opportunities

• Data grid: replica catalogs done properly, bandwidth (esp. regional), certificate authority, virtual data grids?, …

• Services for uploading user codes: is a sandbox needed?, compiler and library versions, is a cluster needed?

• Grid management - synchronising Globus, Tomcat, … versions, legacy softwarelegacy software, account names, geographical location, firewalls, … - use MDS?

2004 ARC LIEF grant2004 ARC LIEF grant

• 10 partners!

• more data archives on-line

• theory realisations and codes on-line

• more tools developed with special focus on server-based visualisation

• construction of the Australian Australian Astronomy Grid…Astronomy Grid…

The Australian Astronomy Grid 2004The Australian Astronomy Grid 2004

http://www.aus-vo.org