The Australian Virtual Observatory e-Science Meeting School of Physics, March 2003 David Barnes

What is a Virtual Observatory? A Virtual Observatory (VO) is a distributed, uniform interface to the data archives of the worlds major astronomical observatories. A VO is explored with advanced data mining and visualisation tools which exploit the unified interface to enable cross-correlation and combined processing of distributed and diverse datasets. VOs will rely on, and provide motivation for, the development of national and international computational and data grids.

Scientific motivation Understanding of astrophysical processes depends on multi-wavelength observations and input from theoretical models. As telescopes and instruments grow in complexity, surveys generate massive databases which require increasing expertise to comprehend. Theoretical modeling codes are growing in sophistication to consume available compute time. Major advances in astrophysics will be enabled by transparently cross-matching, cross-correlating and inter-processing otherwise disparate data.

Aus-VO in 2003 Phase A funded AUD 260K by a 2003 ARC grant: –The University of Melbourne –The University of Sydney –CSIRO Australia Telescope National Facility –Anglo-Australian Observatory Funded common format on-line archive projects: –HIPASS: HI spectral line and 1.4-GHz continuum survey –SUMSS: 843 MHz continuum survey –ATCA archive: spectral line and radio continuum images –2dFGRS: optical spectra of >200K southern galaxies

Melbourne Adelaide Canberra Sydney Parkes? Swinburne DataCPU? Data ATNF/AAO Theory? HIPASS Gemini? ATCA MSO 2dFGRS RAVE SUMSS CPU Theory GrangeNet... thinking about the Aus-VO Grid, having data nodes and compute nodes... GrangeNet: Grid and Next Generation Network – a 10 Gbit backbone APAC CPU VPAC CPU Theory

VO Interface & Portal Agreement with AstroGrid (UK e-Science project) to be testers for their data publication and portal creation code. Collecting the necessary resources and intend to have an AstroGrid-based portal serving HIPASS catalogue data for demonstration at IAU General Assembly in July 2003.

The MACHO Grid! MACHO: 8-yr lightcurves for >18 million stars ANU, APAC and MSO have the data on mass store, and are working on a VOTable XML description of the data (metadata). Agreement with San Diego Supercomputer Center to install a storage resource broker (SRB) at ANU, with a view to making the MACHO data available on an international Grid.

Grid-based Visualisation ATNF will build a Java PixelCanvas so that AIPS++ visualisation applications 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.

Grid-based Volume Rendering Agreement between Melbourne and AstroGrid to develop our existing distributed-data volume rendering code into a fully- fledged Grid-Service. Challenge is to interactively render a multi-GB cube at the IAU GA 2003, using GridFTP to transfer the data volume from a remote data warehouse to a remote rendering cluster.

DataGrids for Aus-VO Australian archives range from ~10 GB to ~10 TB in processed (reduced) size. providing just the processed images and spectra on-line requires a distributed, high- bandwidth network of data servers – that is, a DataGrid. users may want some simple operations such as smoothing or filtering, applied at the data server. This is a Virtual DataGrid.

ComputeGrids for Aus-VO More complex operations may be applied requiring significant processing: –source detection and parameterisation –reprocessing of raw or intermediate data products with new calibration algorithms –combined processing of raw, intermediate or "final product" data from different archives These operations require a distributed, high- bandwidth network of computational nodes – that is, a ComputeGrid.