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Prototype system of the Japanese Virtual Observatory Masahiro Tanaka, Yuji Shirasaki, Satoshi Honda, Masatoshi Ohishi, Yoshihiko Mizumoto (NAOJ), Naoki Yasuda (U. Tokyo), Yoshifumi Masunaga (Ochanomizu U.) http://jvo.nao.ac.jp/ The Japanese Virtual Observatory (JVO) aims at providing easy access to federated astronomical databases (especially SUBARU, Nobeyama and ALMA) and data analysis environment using the Grid technology. JVOQL (JVO Query Language) is defined in order to write request conditions for federated databases. The JVO prototype system is developed for the purpose of technical feasibility study, including functionality of JVOQL, remote operations using Globus toolkit, and automatic search for services. The prototype consists of several components: JVO portal where users can look up astronomical catalogs and build a query request easily, distributed data servers containing data of Subaru Suprime-Cam and 2MASS, and JVO controller to decompose a request written in JVOQL into individual queries for data servers. We confirm that this prototype actually works as federated databases and that the Grid service of the Globus toolkit version 3 has adequate performance for the federation of distributed databases. Introduction Increasing amount of Astronomical Data Nobeyama Subaru ALMA : ~1TB/yr : ~20TB/yr : ~?PB/yr etc. Cumbersome task for every instrument: Data retrieval, transfer, analysis, etc... JSP DB Navigator JSP • JVOQL Parser Scheduler Executer Several-hour task in conventional ways. Five-minute task with JVO ! Astro DB RFT Met aDB Astro DB RFT Scheduler Remote Execution with Grid Service Grid Service Met aDB Grid Service User DB Data Analysis JVO features 1.Grid environment using Globus Toolkit Globus Toolkit ver.3 is employed for JVO Prototype ver.2. “Grid Service” of GTK3 is used for remote operation. RFT (Reliable File Transfer) and SFS is used for file transfer between portal and remote servers. 2.JVOQL (JVO Query Language) for database federation We defined JVOQL to write search condition to federate distributed database. JVOQL is based on SQL, widely used as a language for a relational database, and provides functionalities of cross match and retrieval of image and spectrum. User Operation Windows After authentication, choose catalogs and specify retrieval condition using JVOQL editor. 3.Multi-user and multi-task JVO includes authentication system. It certifies users, permits access to JVO system, and manages users’ processes and storage areas. 4.Metadata management Metadata is information on remote servers, services and observational data. We defined XML expressions of metadata and stored them into Registry, which is constructed using XML DB. That enables automated federation of distributed database and analysis servers, and contents of available observational data in JVO. Work flow for Gravitational lens search 1.Retrieve Subaru catalog data in a specified region. ↓ 2.Calculate brightness ↓ 3.Define condition to select quasars. ↓ 4.Make a list of pair quasar objects. ↓ 5.Retrieve image data of the pair objects ↓ 6.Narrow candidates by analyzing the image data. OAI-PMH Grid Service Job Status Executer Remote Execution with Grid Service Grid Service Status monotor OAI-PMH As an example of research using JVO, here exhibits a series of processes for searching gravitational lens object in data obtained with Subaru telescope. Server Info Registry (XMLDB) Server Info • Controller Grid Service OAI-PMH JVO Prototype Analysis Command Simple Analysis Source Extraction(Sextractor) • Hyper-Z • Image Operation • Photometry JSP • Specific Analysis • Gravitational Lens • Dust Distribution • Chemical Evolution • VOTable Viewer • Plotter Image • Viewer • Spectrum Viewer • Multi-catalog Superpose Plot • Multi-wavelength Image Plot • Result (XML) OAI-PMH To be used by general education, amateur astronomers and families as well as researchers. Parsed Query JSP Data transfer with SFS JVOQL Metadata Query (XPath) Status • Make multi-wavelength research easy due to unified data manipulation regardless of observational instruments. Job Status Controller Job Element • Internal data analysis reduces data transfer. Status Monitor OAI-PMH • Enables observation regardless of time and place. JCOQL Editor •DB Search with Resource finder •UCD finder •Name Revolver •Status Monitor Servlet Analysis Interface Data Display JSP • DB Search with Resource finder Met aDB Benefit of VO... Query interface User Register • User Authentication • Data transfer with SFS VO is a system to observe “the Universe in computers”, which is constructed by employing these information technologies. User Management Query Command (JVOQL) JVO System Conventional methods are inadequate. Information science takes important roles in Astronomy. Development of JVO User Interface Combination of Information technologies and Astronomy •Web service •Grid technology •Data Mining •Database technology •Visualization •etc… The main purpose of the development of JVO prototype is to test functionality of employed technologies. JVO prototype version 2 has currently been developed. Retrieval condition is reflected in JVOQL Editor. Result Display Windows Search result is obtained in the form of VOTable, which is international standard to express table data in the XML form, and displayed on WWW browser. Registry is used to find available data in JVO and to construct work flow of remote procedure calls. JVOQL parser decomposes JVOQL, Scheduler generates work flow, and Executer performs remote procedure calls. It is easy to add new analysis tools for conducting particular science. ← ↑ Retrieve and display SXDS data ↑ Retrieve SDSS QSO and display spectra