We present the design and implementation of the Japanese Virtual Observatory (JVO) system. JVO is a portal site to various kinds of astronomical resources distributed all over the world. We have developed five components for constructing the portal: (1) registry, (2) data service, (3) workflow system, (4) data analysis service (5) portal GUI. Registry services are used for publishing and searching data services in the VO, and they are constructed using an OAI-PMH metadata harvesting protocol and a SOAP web service protocol so that VO standard architecture is applied. Data services are developed based on the Astronomical Data Query Language (ADQL) which is an international VO standard and an extension of the standard SQL. The toolkit for building the ADQL-based service is released to the public on the JVO web site. The toolkit also provides the protocol translation from a Simple Image Access Protocol (SIAP) to ADQL protocol, so that both the VO standard service can be constructed using our toolkit. In order to federate the distributed databases and analysis services, we have designed a workflow language which is described in XML and developed execution system of the workflow. We have succeeded to connect to a hundred of data resources of the world as of April 2006. We have applied this system to the study of QSO environment by federating a QSO database, a Subaru Suprim-Cam database, and some analysis services such a SExtractor and HyperZ web services. These experiences are described is this paper.
The Japanese Virtual Observatory (JVO) project has been conducted by the National Astronomical Observatory of Japan (NAOJ). JVO aims at providing easy access to federated astronomical databases (especially SUBARU, Nobeyama and ALMA) and data analysis environment using the Grid technology. We defined JVOQL (JVO Query Language) for efficient retrieval of astronomical data from a federated database. We then constructed the first version of the JVO prototype in order to study technical feasibility including functionality of JVOQL, remote operations using Globus toolkit. The prototype consists of several components as follows: JVO portal to accept users' requests described in JVOQL, JVO Controller to parse them into individual query requests, and distributed database servers containing Suprime-Cam data of the Subaru telescope and 2MASS data. We confirmed that this prototype actually worked to access to a federated database. We construct the second version of the JVO prototype system to improve usability, which includes new user interfaces, efficient remote operations, and introduction of analysis tools. In the course of this, Grid service and XML database is employed. In this presentation we describe its design and structure of the new JVO prototype system.
The Wide-field X-ray Monitor (WXM) is one of the scientific
instruments carried on the High Energy Transient Explorer 2 (HETE-2)
satellite launched in October 2000. The WXM consists of three elements: (1) four identical Xe-filled one-dimensional position-sensitive proportional counters, two in the spacecraft X-direction and two in the Y-direction, (2) two sets of one-dimensional coded apertures orthogonally mounted above the counters in the X and Y-direction, and (3) the main electronics that processes analog signals from the counters. The WXM counters are sensitive to X-rays between 2 keV and 25 keV within a field-of-view of about 1.5 sr with a total detector area of about 350 cm<sup>2</sup>. The combination of the apertures and the counters provides GRB locations with accuracy ~10 arcmin. The counters and electronics are developed and fabricated by RIKEN, and the apertures and on-board software are designed and provided by Los Alamos National Laboratory. The WXM plays a major roll in the GRB localization and its spectroscopy in the energy range between 2 keV and 25 keV. During the first year of observations, a number of steady X-ray sources as well as high-energy transients were detected with the WXM. Observing Crab nebula and Sco X-1, we have calibrated the detector alignment between the WXM and the optical camera system with 2 arcmin accuracy. As of 29 July 2002, nineteen GRBs have been localized with the WXM in the 18 months of stable operations. Twelve of them were reported to the GCN within a delay of 10 hours, and 4 optical transients were identified by ground based telescopes. The energy response of the detectors has also been calibrated using the Crab spectrum. We report the in-orbit performance of the WXM instrument during the first 18 months.