In 2006, NAOJ proposed to construct the Hyper Suprime-Cam (HSC) as a second generation instrument for Subaru telescope. This is a very wide-field camera covering 1.5 degrees of sky at a time. The focal plane area to be covered is 530mm. A total of 116 2kx4k CCD detectors are placed adjacent to each other in order to cover this large field of view. The HSC is a prime focus camera, and enlarges the field of view (FOV) of Subaru, as provided by the first generation camera Suprime Cam, by a factor of 10. HSC was completed in 2013 and is the largest CCD camera in the world, and has a total performance, as measured by the product of the telescope aperture area and the field of view, which exceeds that of all other telescopes. Only the planned LSST will have a better performance, but that will not be completed before 2018.
The main scientific goal of the HSC will be weak lensing studies over large areas of the sky. Approximately 1400 square degrees will be surveyed in 6 years from 2014. Weak lensing distortions of background galaxies due to the large scale structure, so called cosmic shear, will be examined. From statistical properties of cosmic shear, the properties of dark energy will be constrained. Along with the weak lensing study, a large survey project is approved to use about 300 nights of HSC and Subaru to cover interesting science topics with the large dataset.
ASIAA has been invited by NAOJ to join in on this project in 2007. This is the continuation of the growing collaboration between Taiwan and Japan. In 2005, ASIAA joined the ALMA project via NAOJ. In the same year, the East Asian Core Observatories Association (EACOA) was established to promote joint future developments in astronomy in Asia. Taiwan, together with Japan, China, and Korea, are founding members of EACOA. Astronomy is developing rapidly in North America and in Europe. Asia can compete effectively by investing wisely in specific collaborative projects.
The MOU between ASIAA and NAOJ was signed in Oct 2008 to join the HSC project, by helping to construct specific parts of the instrument. The experience gained through the TAOS and WIRCam projects will be applied. The HSC is planned to be finished by 2012. Meanwhile, the MOU also aims for a long term collaboration with Subaru telescope. The official partners of HSC now include NAOJ, University of Princeton and ASIAA. The three sides will work together on the HSC survey plan.
After the completion of HSC, ASIAA continued to work with Subaru telescope for the development of Prime Focus Spectrograph (PFS). PFS will provide the spectroscopic observation capability which is complementary to the imaging capability of HSC. PFS is a multi-fiber spectrograph to provide simultaneously low resolution spectrum for two thousands of targets. PFS is scheduled to be finished around 2018 and a PFS survey is planned following the HSC survey for the studies of cosmological galaxy surveys, Galactic archaeology, and galaxy/AGN evolution.
Meanwhile, ASIAA is also working on the MOIRCS upgrade with Subaru telescope. MOIRCS is the major near-IR instrument of Subaru telescope. The upgrade of MOIRCS includes the installation of new Hawaii-2RG arrays with ASIC controller and Integral Field Unit (IFU) units. The upgrade work started in 2014 and is planned to be completed in 2015.