M. C. Leoni 1 , T. A. McGlynn 2 , R. D. Williams 3 1 European Southern Observatory, Germany 2 HEASARC, Greenbelt -

1. M. C. Leoni 1, T. A. McGlynn 2, R. D. Williams 3 1 European Southern Observatory, Germany 2 HEASARC, Greenbelt - MD, USA 3 Caltech, Pasadena - LA, USA The VO Reality Thanks to the increased effort in the development and spread of the “VO novel”, the past year saw a spur in the creation of software for the Virtual Observatory: including both prototypes and released tools, produced by the national VO projects, members of the International Virtual Observatory Alliance (IVOA). Following is a comprehensive list of software for the VO – as of this writing. Highlights are on main features and the way each one interacts and interoperates with the others using common industry standards as well as astronomy-specific ones developed within the IVOA. Grid and Web Services Several Web Services have been created, both wrapping already existing services as well as exposing new functionalities. Grid services are in the making to allow workload distribution and resource sharing. ACE – (Astronomical Catalogue Extraction) Based on the well-known SExtractor tool, this web service exposes the same capabilities to the web world: http://wiki.astrogrid.org/bin/view/Astrogrid/AVODemoDesign Aladin Image – gives image URL locations or images based on DIME: http://cdsweb.u-strasbg.fr/cdsws/aladin_image.gml Astronomical Coordinates – provides astrnomical coordinate translation http://cdsweb.u-strasbg.fr/cdsws/astroCoo.gml Cosmic Distances – XML ws to calculate different distance measures in a given cosmology: http://voservices.net/Cosmology/ws_v1_0/Distance.asmx Filter Profiles – access profiles of well-known astronomical instruments: http://voservices.net/filter/ GLU Resolver – resolves catalogue tags through GLU: http://cdsweb.u-strasbg.fr/cdsws/glu_resolver.gml Grist – Grid sevices for data mining in astronomy: http://grist.caltech.edu/ NED – XML Web Service interface to NED : http://voservices.net/NED/ws_v1_0/NED.asmx Name Resolver – resolves names for VizieR, Simbad, NED: http://cdsweb.u-strasbg.fr/cdsws/name_resolver.gml SDSS Cas – XML Web Service interface to the SDSS Catalog Archive Server: http://voservices.net/CasService/ws_v1_0/CasService.asmx SDSS Image Cutout – SDSS DR1 finding chart tool: http://skyserver.sdss.org/dr1/en/tools/chart/chart.asp Spectrum – portal for VO Web Services to acess data from SDSS DR1 and 2dFGRS: http://voservices.net/spectrum/ UCD – resolves UCD tag, gives the complete list of UCDs, gives the list of UCD contained in a catalogue: http://cdsweb.u-strasbg.fr/cdsws/ucdClient.gml VizieRWS – Web Service to access VizieR catalogues: http://cdsws.u-strasbg.fr/axis/services/VizieR Tools Since the main format to exchange data is VOTable, most of the tools first developed regard the manipulation of such VO standard-based files. The list includes visualization tools, filters as well as software libraries. JAVOT – Java Parser for VOTable: http://us-vo.org/VOTable/JAVOT Mirage [VO-enabled] – Java –based wrapper for Mirage, a tools for exploratory analysis and visualization of classification and proximity structures of multi-dimensional numerical data from an arbitrary domain of study: http://skyservice.pha.jhu.edu/develop/vo/mirage/ Specview – java application for 1-D spectra visualization and analists of astronomical spectrograms: http://www.stsci.edu/resources/software_hardware/specview TOPCAT – interactive graphical viewer and editor for tabular data: http://www.starlink.ac.uk/topcat/ VOTFilter – enables the import of VOTable documents into OpenOffice Calc spreadsheet; written in java, this XML filter can be downloaded from: http://www.china-vo.org/VOTable Filter for OpenOffice Calc.htm VOPlot – a java visualization tool, to manipulate VOTable data. Available as standalone application or a web-based one, the latter being an applet. More info at http://vo.iucaa.ernet.in/~voi/voplot.htm VOSpec – Java applet tool to handle VO spectra: http://pma.standby.vilspa.esa.es:8080/vospec/index.html VOTable Java Streaming Writer – java package to convert files in different formats (e.g. ASCII) to VOTable: http://vo.iucaa.ernet.in/~voi/votableStreamWriter.htm VOTool – package for allowing IRAF system to handle VOTable: http://iraf.noao.edu/projects/votool/ Xmatch (CDS) – Aladin plug-in http://www.euro-vo.org/twiki/bin/view/Avo/CDSXMatchPlugin All the VO software uses these protocols to interoperate with each other. Up to now, the main point in the structure is the creation of a registry containing all the available resources (described using the VOResource metadata standard), thus allowing software to automatically discover and use what it needs. Formats & Protocols VOTable XML dialect SIAP – (Simple Image Access Protocol) SSAP – (Simple Spectrum Access Protocol) ADQL – (Astronomical Data Query Language) XML translation of SQL-based queries to be exchanged among VO servers. SOAP & XML – (Simple Object Access Protocol, eXtensible Markup Language) Separation is not as definite as depicted in the overall architecture picture. Due to the existing strong relationships amongst applications, some of them may actually fall under different parts of this representation (or contain software with functionalities belonging to more than one area). Besides using well known industry-level protocols, the VO is developing other standards to help the interoperability and to improve performance. Prototypes & more Aladin for AVO – Interactive sky atlas, http://www.euro-vo.org/twiki/bin/view/Avo/SwgDownload to visualize images, superimpose catalogues, interactively access data & info from online databases. Astrogrid – The suite developed covers all the needs a data centre has to publish its data archive: http://www.astrogrid.org/maven/docs/SNAPSHOT/astrogrid-software-site/ Atlasmaker – Grid-based software for building atlases fo astronomical images: http://www.cacr.caltech.edu/projects/nvo/atlasmaker/ Carnivore – VO registry with publishing, querying and harvesting capabilities (uses XML database): http://mercury.cacr.caltech.edu:8080/carnivore DataScope – (Data Inventory Service) Quick look at all data available for a given position in the sky: http://heasarc.gsfc.nasa.gov/vo/ Montage – Grid software for mosaics computation: http://montage.ipac.caltech.edu/ NCSA Registration Portal – portal that allows data providers to make their resources VO visible: http://nvo.ncsa.uiuc.edu/nvoregistration.html NVO Registry – searchable registry, exposes keyword/SQL interface, http://nvo.stsci.edu/VORegistry Open SkyQuery – based on Microsoft.net technolog, offers SOAP services to perform distributed astronomical queries using VOTable and ADQL: http://openskyquery.net/Sky/skysite/ Peagsus – (Planning for Execution in Grids) system to map and execute workflows on the Grid: http://pegasus.isi.edu/ SDSS Sky Server – provides access to SDSS DR3 data: http://cas.sdss.org/astro/en/ SkyQuery.net – prototype of a federated database application: http://www.skyquery.net/main.htm SkyView – panchromatic image atlas, generates images of any part of the sky at wavelengths in all regimes from radio to gamma-ray: http://skys.gsfc.nasa.gov/ VirtualSky – portal to a panchromatic sky atlas: http://www.virtualsky.org/