The Large Size Telescopes, LSTs, located at the center of the Cherenkov Telescope Array, CTA, will be sensitive
for low energy gamma-rays. The camera on the LST focal plane is optimized to detect low energy events based
on a high photon detection efficiency and high speed electronics. Also the trigger system is designed to detect
low energy showers as much as possible. In addition, the camera is required to work stably without maintenance
in a few tens of years. In this contribution we present the design of the camera for the first LST and the status
of its development and production.
The astrobiology-related activities in the National Astronomical Observatory of Japan (NAOJ) is reported. The 45m radio telescope of the NAOJ was used to search for the interstellar glycine without success, concluding that the former claim on the detection of interstellar glycine has not been confirmed. Future observations by ALMA would clarify the existence of glycine in space. The Okayama Astrophysical Observatory of the NAOJ has been used to detect ten extrasolar planets. The Subaru telescope has also been used, under international collaborative program, to search for extrasolar planets, leading to detection of two planets. A unique trial to search for extrasolar planets by using low frequency radio data was conducted without success, however, such a method would be a basis toward radio searches by future sensitive radio astronomy instruments such as SKA and LOFAR. NAOJ has a project to search for extraplanets by a highly sensitive coronagraph. This project has also designing the Japanese Terrestrial Planet Finder for future space-based search for the Earth-type planets.
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 International Virtual Observatory Alliance (IVOA: http://www.ivoa.net) represents 14 international projects working in coordination to realize the essential technologies and interoperability standards necessary to create a new research infrastructure for 21st century astronomy. This international Virtual Observatory will allow astronomers to interrogate multiple data centres in a seamless and transparent way, will provide new powerful analysis and visualisation tools within that system, and will give data centres a standard framework for publishing and delivering services using their data. The first step for the IVOA projects is to develop the standardised framework that will allow such creative diversity. Since its inception in June 2002, the IVOA has already fostered the creation of a new international and widely accepted, astronomical data format (VOTable) and has set up technical working groups devoted to defining essential standards for service registries, content description, data access, data models and query languages following developments in the grid community. These new standards and technologies are being used to build science prototypes, demonstrations, and applications, many of which have been shown in international meetings in the past two years. This paper reviews the current status of IVOA projects, the priority areas for technical development, the science prototypes and planned developments.
The POrtable Submillimeter Telescope (POST) was put into operation in Nov. 1999. In this paper, we briefly introduce the control system of the telescope, including both hardware and software. The hardware is based on the S-Bus of a SUN workstation. Industrial standard I/O interfaces are adopted to fulfil different purposes of information transfer. Pulse width modulation (PWM) and harmonic driver are adopted to the antenna driving system, which is controlled in a mode of closed-loop positional feedback. The control software is to accomplish various observing and diagnostic functions of the telescope. The software is designed as a centralized real-time, multi-task package on the base of the UNIX platform. Present version of the entire control software includes 14,000 lines of source code in C language. The control system as a whole realizes all functions of a highly automatic all-sky submillimeter telescope used to observe cosmic submillimeter line radiation, particularly the neutral atomic carbon line at 492GHz. Besides, the system can be operated remotely. The principle as well as the software can be applied to control other precision radio telescopes.
The Mt. Fuji submillimeter-wave telescope has been operated since November 1998 to survey neutral atomic carbon (CI) toward the Milky Way. It has a 1.2 m main reflector with a surface accuracy of 10 micrometer in rms. A dual polarization superconductor-insulator-superconductor (SIS) mixer receiver mounted on the Nasmyth focus receives 810/492/345 GHz bands in DSB simultaneously. An acousto-optical spectrometer (AOS) has 1024 channels for 0.8 GHz bandwidth. The telescope was installed with a helicopter and bulldozers at the summit of Mt. Fuji (alt. 3725 m) in July 1998 after a test operation at Nobeyama for a year. It has been remotely operated via a satellite communication from Tokyo or Nobeyama. Atmospheric opacity at Mt. Fuji was 0.4 - 1.0 at 492 GHz in 30% of time and 0.07 - 0.5 at 345 GHz in 60% of time during winter five months. The system noise temperature was typically 1200 K (SSB) at 492 GHz and 500 K (DSB) at 345 GHz. The beam size was measured to be 2.'2 and 3.'1 at 492 and 345 GHz, respectively. We have conducted a large-scale survey of the CI (492 GHz) and CO (3 - 2: 345 GHz) emission from nearby molecular clouds with total area of 10 square degrees. We describe the telescope system and report the performance obtained in the 1998 winter.
The control system for the 45 m radio telescope and the millimeter array at the Nobeyama Radio Observatory, which has been used since 1982, has a centralized structure based on an IBM compatible mainframe. However, due to developments of new instruments for these telescopes, the upgrading of the telescope control system has been started. To provide better availability and flexibility, the new control software is completely distributed, being based on LANs interconnecting workstations and personal computers. The new system is functionally divided into three levels: console (first layer), followed by supervisor and data archiver (second layer), and by local controllers for each device (third layer).