Brief history of Japan’s involvement with the SKAO
The Japan SKA consortium was established in May 2008. Japanese SKA activities are led by the Japan SKA consortium in which more than 250 Japanese scientists and engineers are participating. Japan has been seeking a way to participate in the SKA projects since then. The SKA is listed in the Japanese Master Plan of Large Research Projects, compiled by the Science Council of Japan – the organisation representing the Japanese scientific community across all fields of sciences. The National Astronomical Observatory of Japan (NAOJ) has established an “SKA study group” to promote Japanese participation in the SKA project. Although Japan is not yet a member, a representative from NAOJ has been participating in the SKA board meetings as an observer.
Supporting the SKAO
Japan has been an observer first to the SKA Organisation Board of Directors and, since its creation in 2021, to the SKAO Council, allowing continuous interaction between the SKA Project and the Japanese community and discussions about the future Japanese participation in the SKAO as a full member. Several members of the Japanese scientific community have been seconded to the SKA Organisation and subsequently the SKAO since 2014.
Science Interest for Japan
Japan SKA consortium comprises 10 science working groups working on EoR, Cosmology, Galaxy evolution, Pulsar, Cosmic magnetism, VLBI, ISM, Transient, Star and planet formation, and Planets. Japanese astronomers are members in 13 of the 14 SKA science working groups and focus groups.
Building the SKAO
Japan has joined the Assembly, Integration, & Verification (AIV) Work Package. NAOJ SKA1 study group members has started working with AIV consortium members.
Japan SKA consortium members are working closely with Mizusawa VLBI observatory, which operate the VERA telescope. Skills in all aspects of VLBI science and its techniques are expected to help the AIV process during the SKA construction and to help the SKAO to develop VLBI mode.
Developing New Technologies
Mizusawa VLBI observatory has been working on development of fast analogue-to-digital converter (ADC) as shown in Figure of OCTAD, which can sample analogue data with 8-Gsps 3-bit up to the frequency of 50 GHz. Direct-sampling observation is possible without down-convertor using such a fast ADC. Since down-converting component is not necessary with direct-sampling system, the system can be simpler. At the same time, high-speed data recording is possible using this new ADC. These developments might be helpful for the SKA telescopes.