Google Sky CANS 2007 Aug 25 26 2007

Google Sky CANS 2007, Aug. 25 -26, 2007, Xi'an

Worldwide R&D of Virtual Observatory Chenzhou CUI Chinese Virtual Observatory Project National Astronomical Observatory of China CANS 2007, Aug. 25 -26, 2007, Xi'an

Content • VO Introduction • IVOA status, specifications and highlights • R&D activities from China-VO CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

VO concept • Virtual Observatory (VO) is a data-intensively online astronomical research and education environment, taking advantages of advanced information technologies to achieve seamless, global access to astronomical information. • The power of the World Wide Web is its transparency. It is as if all the documents in the world are inside your PC. The idea of the Virtual Observatory is to achieve the same transparency for astronomical data and other related information (Quinn et al. 2004). CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

IVOA in Growth • International Virtual Observatory Alliance (IVOA) • formed in June 2002 • with a mission to facilitate the international coordination and collaboration necessary for the development and deployment of the tools, systems and organizational structures necessary to enable the international utilization of astronomical archives as an integrated and interoperating virtual observatory. CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Science driven, technic enabled VO drivers : science • multi-archive research • Precision Cosmology • The Time Domain • A Panchromatic approach to the Universe… CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Science driven, technic enabled VO drivers : technology • hardware trends – ops, storage, bw : all 1000 x/decade – data i/o bw 10 x/decade • data avalanche – CCD array – digital sky survey – numerical simulation CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

VO framework • agreed standards • inter-operable data collections • inter-operable software modules • no central VO-command - its not a thing - its a way of life CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

What the Virtual Observatory is… • A suite of international standards for the discovery, exchange, intercomparison, and analysis of networkaccessible astronomical data • A data access and analysis environment that exploits the emerging computation/software/data It is not a thing Grid • A framework for data processing that enables and encourages the re-use of algorithms • A tool for science planning: Identify gaps in coverage of parameter space. Which new missions, instruments, experiments will have largest impact? • A catalyst for world-wide access to astronomical archives • A routinely used tool of the research astronomer • A vehicle for education and public outreach CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

what is needed ? • • • global standards well funded data centres working data services infrastructure software VO aware client tools VO aware data mining services CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

IVOA Protocols key for interoperability CANS 2007, Aug. 25 -26, 2007, Xi'an

Protocol List • • • • • VOTable FITS Cone Search Protocol Simple Image Access (SIA) Protocol Simple Spectral Access (SSA) Protocol Sky. Node Astronomical Data Query Language (ADQL) Uniform Column Descriptors (UCDs) Space-Time Coordinates (STC) IVOA Identifiers VO Registry Resource Metadata Registry Access Protocols OAI VOEvent NESSSI VOSpace PLASTIC Common Execution Architecture Request-Object Management Environment (ROME) CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Formats • VOTable – XML format for tabular information • Catalog query results • List of images or spectra • Lists of resources • Includes UCDs for columns • FITS – Standard astronomical binary data format – Images, spectra, … CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Data Access Protocols • Cone search • Simple image access • Simple spectral access • Sky. Node – – Simple query around a given region Returns VOTables – – What images overlap a given region? Create me an image of this region. First step produces VOTables with links to image User downloads images as FITS in second stage – – What spectra are available within this region More sophisticated than SIA (includes support for Data Models) but uses comparable framework – – – SOAP Web-Service based Sophisticated access to tables Supports distributed queries Uses ADQL Should eventually subsume Cone-search CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Query languages • Astonomical Data Query Language (ADQL) – Enhanced version of SQL to support astronomical queries • Positional cross-correlations (XMATCH) • Complex regions on the sky (REGION) – Both SQL-like and XML representations CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Semantic content • • IVOA identifiers – Scheme for providing unique identifiers for any thing that needs to be distinguished. Services, requests, … – ivo: //authority_controlled_string#subresource – Used in registries and other protocols Resource metadata – Standardized format for the description of a service, data collection, facility. – XML format based on the Dublin-core metadata descriptions for published resources. – Used inside registries. Uniform Column/Content Descriptors (UCDs) – Standardized names for table columns with relatively high degree of specificity. – pos. eq. ra or phot. flux; em. ir – Used in VOTables and by Cone search and SIA Space/Time Coordinates – Way of specifying points or regions of space-time. – Can be simple or very complex – Used in ADQL and VOEvent CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Discovering Resources • Registry – Collection of resources that users can find included Cone Search, SIA, SSA and Sky. Nodes. • • • – User access via registry access protocol – Registry-registry communication via OAI – Some publishing registries are meant to be seen only by other registries Registry access – How users query the registry – In standards process Open Archive Interface (OAI) – Library community standard – Registry-registry communication to ensure that all registries are up to date. VOEvent – VO protocol for publishing and receiving notice of transient/urgent events – Describes events using STC CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Accessing and Controlling Computer Resources • • • NESSI – NVO Extensible, Scalable, Secure Service Infrastructure – Provide access to protected resources, especially Grid computational resources. – Make it easy to do simple things. – First implementations just coming on-line VOSpace – Access to storage resources in a standardized way. PLASTIC – Platform for Astronomical Task Inter. Communication – Applications publish and receive notifications of events from other applications (e. g. , selection of a given object) to enable coordinated actions. – TOPCAT – Aladin – Deployed but still experimental. Common Execution Environment (CEA) – Script/pipeline environment with security and such incorporated (Astrogrid) ROME – Handle and schedule tasks that involve remote resources. CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Highlights from VO • VO Infrastructures • VO-oriented application • Miscellaneous tools CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Astrogrid Components • • Registry Community File. Manager/Filestore Workflow& Job Execution Service (JES) Common Execution Architecture (CEA) Data. Set Access (DSA) Workbench CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Aladin V 4 – CDS (Euro-VO) • Aladin v 4 an interactive software sky atlas developed by CDS Multi. View, multi. Projection Resampling Blinking: builds on the fly image sequences (slow movies) GIF, JPEG and PNG support Cut graph: along any segment Cross match algorithm: for better object catalog analysis Multi-language CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

NVO Core Services • NVO Registry Portal: Find source catalogs, observation logs, image archives, and other astronomical resources registered with the NVO • Data. Scope: Discover and Explore Data in the Virtual Observatory • Open Sky. Query: Cross match yoru data with numerous catalogs • NVO Spectrum Services: Search, plot, and retrieve SDSS, 2 d. F, and other spectra • Web Source Extractor Upload images to SExtractor and crosscorrelate the objects found with selected survey catalogs. CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

VOPlot Tools from VO-India A VO-I + CDS collaboration VOPLot 3 D VOMega. PLot CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

History and current status CANS 2007, Aug. 25 -26, 2007, Xi'an

R&D Focuses • China-VO Platform – 中国虚�天文台系�平台的开� • Unified Access to On-line Astronomical Resources and Services – 国内外天文研究�源的�一�� • VO-ready Projects and Facilities – 支持VO的�目与���施 • VO-based Astronomical Research Activities – 基于VO的天文研究示范 • VO-based Public Education – 基于VO的天文科普教育 CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Two XSLT transforms • VOFilter – an XML filter for Open. Office. org Calc to open VOTable files – http: //services. china-vo. org/vofilter/ • VOTable 2 XHTML – a stylesheet to transform VOTable data into HTML/XHTML format – http: //services. china-vo. org/votable 2 xhtml/ CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

VO Data Access Service (VODAS) • An OGSA-DAI based service system to provide unified access to astronomy data, including catalogs, images and spectra. • Goals of VO-DAS – Supporting high volume data query – Interlinking distributed and heterogeneous archives • catalogs, images, spectrums – Providing a software that works for astronomers • OGSA-DAI Supported Asynchronous Data Access Service – OGSA-DAI is a middleware product which supports the exposure of data resources, such as relational or XML databases, on to grids. – Work with Globus Toolkit 4 – WSRF interface – Good wrapper for variant databases – Asynchronous query supported – Available for large dataset CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Status • An Alpha version of VO-DAS was ready – Query Workflow • Synchronous Query • Asynchronous Query on multiple Data. Nodes CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Sky. Mouse: Touch the sky with your mouse • Not like some VO efforts on unified access systems, for example, NVO Data. Scope, Sky. Mouse tries to show a comprehensive overview for a specific object, but not to snatch as much data as possible. CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

VO Trends • VO is inevitable, a new way of doing science • Present on every physical scale today, not just astronomy (NEON, Neptune, CERN, MS) • Driven by advances in technology, and economics, mapped onto society CANS 2007, Aug. 25 -26, 2007, Xi'an 3/3/2021

Q&A ? www. CANS 2007, Aug. 25 -26, 2007, Xi'an . org 3/3/2021