Japanese Virtual Observatory Project Abstract : The National Astronomical Observatory of Japan (NAOJ) started the Japanese Virtual Observatory (JVO) project since April JVO utilizes the Grid technology to combine several remote computational resources. We have defined the query language for the JVO to federate multiple astronomical databases and constructed a prototype of the JVO to confirm whether federated databases can be accessed through Grid technology. More information is provided at: Masatoshi OHISHI, Yoshihiko MIZUMOTO, Naoki YASUDA, Yuji SHIRASAKI, Masahiro TANAKA, Satoshi HONDA (NAOJ) and Yoshifumi MASUNAGA (Ochanomizu Univ. and NAOJ) in Collaboration with Fujitsu Ltd. Contact Address: Federate with more data: Data of SUBARU open use/Nobeyama Radio Observatory Interoperability with other VOs : Toward International VO CPU intensive analysis tools: Deconvolution, image subtraction…, Run on PC cluster via GRID Data mining / visualization tools: Manage huge amount of data Future Plan The JVO Query Language JVOQL has an ability to query image data without referring to catalogs. This ability is useful for multi-color or multi-epoch analyses. The above JVOQL example shows how to obtain R-band images taken by SUBARU and K-band images by select s.a, t.a,... from SUBARU.R s, 2MASS.K t,... where (s.AREA() OVERLAP t.AREA()) as a create view myEROtable as select s.Bmag, s.Rmag, t.Hmag, t.Kmag,..., sr.BOX(POINT(s.ra,s.dec),w,h) as Rimage, tk.BOX(POINT(s.ra,s.dec),w,h) as Kimage,... from SUBARU s, 2MASS t,..., SUBARU.R sr, 2MASS.K tk,... where XMATCH(s, ｔ,...) < 3 arcsec and (s.Rmag-t.Kmag) > 6 mag and BOX(POINT(ra0,dec0), w0, h0) and... Specify search area with the same syntax as cutout image specification. Create view with the user specified name in JVO system. Select attributes from each catalog server. Column names can be expressed in UCD. Select the catalog server. Select the image data server. Cross-match distributed catalogs. Query condition based on distributed catalog. Select cutout images from each image data server. Image area can be specified by BOX or CIRCLE operand. The JVO Query Language (JVOQL) is used in JVO as a language to specify a variety of user queries. The JVOQL has been designed to have similar grammar with SQL for the relational database with the additional functionalities to handle image data and cross-match among distributed databases. The parser of JVOQL communicates with the registry of available databases and issues a series of queries to distributed databases. JVOQL together with SkyQuery are adopted as a prototype of the query language for IVO. SUBARU.R s2MASS.K t s.AREA()t.AREA() AREA table cutout request OVERLAP s t a1 a2 a3 Partition to small segment 2MASS in an area where both SUBARU and 2MASS observed. The operand "OVERLAP" returns overlapped area of the two data. Similarly the operand "X.AREA()" returns the observed area of server X. JVO Prototype Ver 1. Main Control Window Write JVO QL here or use an editor. Open a JVO QL Editor User’s own service User’s own service Security mngmt Resource mngmt MVC MVCMVC JVO Portal JVO Portal Astronomical Catalog Query Service Astronomical Catalog Query Service Globus Toolkit Catalog DB Service Registry Service Registry Researcher Browser for JVO Browser for JVO Viewer for JVO Viewer for JVO Data Archive Service Data Archive Service Data manage DB Data Virtual Observation execution service Virtual Observation execution service Data Analysis service Data Analysis service Service Registry Service Registry Other VO services Other Catalog services Other Catalog services Globus Toolkit JVO GRID Environment Other GRID Environment UDDI server Web Browser Web ブラウザ Services callable through Grid Globus Toolkit V2 Data management Security mngmt Resource mngmt Data management At the beginning, researchers provide the JVO with simple instructions how they plan to use their own ''Virtual Observation''. The JVO portal interprets them and generates a work flow through consulting the UDDI servers, where available JVO services are registered. Based on the work flow, built-in or user-defined services are called. The GRID framework is used for dynamical assignment of distributed resources according to their availabilities. Execution results of the work flow are transferred through GridFTP and presented to the researchers. Three-Tiered Design of the JVO Prototype The first version of JVO prototype has been completed. The design of the JVO prototype is shown as a schematic diagram. We adopted to use the Globus Toolkit 2 for our prototype. However, we also take into account the Web Service concept which is included in the Globus Toolkit 3. The current JVO prototype can communicates with four distributed database, “Subaru Deep Field i’-band” (SDF-i’), SDF-z’, “Subaru XMM Deep Survey” (SXDS), and 2MASS. A main control window provides you to specify a query in The JVO system splits the user input query into pieces of queries for each database, then issues search commands to appropriate servers through a “globus-job-submit” command of Globus Toolkit. This example shows a demo doing a cross-matching search between the two databases SDF-i’ and SDF-z’. At first a search command is issued to the SDF-i’ database server, mizu-g, then the result is transferred to the SDF-z’ database server, minazuki-g, where cross-matching search is executed. Image requests are issued at the last two steps.The query results are transferred through GridFTP in a VOTable format for table data and in FITS for image data. The query result is shown up in a result page, which is a kind of VOTable viewer and provides an easy access to both the table and image data. For graphical viewing of the table data, plotting tool is available. You can specify any column or expression for X/Y axis. Column attributes are displayed by pushing the “column_info” button, where you can also control the column layout. JVO Query Language. You can save/load the QL in a file with the Export/Import button. A QL editor is opened by pushing the editor button and provides an easy way to specify search conditions.