RECENT PROGRESS IN SUBARU AND PROSPECTS OF ASTRONOMY IN JAPAN
KEIICHI KODAIRA
The Subaru telescope is the new major observational facility of Japan in astronomy, constructed at Mauna Kea. The special features of this 8m-class telescope are the sophisticated active main mirror and the wide field prime focus. The latter yields about 30 arcminutes field of view with a focal ratio of F/2. The test observation till now proved high capability of this telescope with sharp stellar images of 0.2 arcsec (FWHM). Some high-lights from the test observation are presented: (1) Color-magnitude diagram of a cluster of galaxies at z=0.4, (2) Luminosity function of young stars born in the Orion Nebula down to K'= 17, (3) Image of an Einstein ring of a gravitational lens, etc. The observational instruments now under commissioning and their prospects are introduced.
The Nobeyama Radio Observatory accommodates a 45m radiotelescope and a 6 element mm-wave Interferometer. The unique 8 channel aucsto-optical spectrometer enabled the detection of the super-high velocity maser clouds around the center of NGC4258, leading to the tightest evidence for the massive black hole. NRO is carrying out the "Rainbow" project by combining the seven telescopes together. The interferometer is intensively used for studies of young stellar objects to elucidate the star formation process. The seventh 10m antenna is completed for sub-mm observation, which shall be allocated in 2001 in the Atacama area of Chile as a forerunner of the LMSA/ALMA project.
The National Astronomical Observatory supports some space programs, in a collaboration with ISAS, such as Yohkoh and Solar-B in solar physics, and Halka, the space VLBI satellite in radio astronomy. NAOJ hosts the TAMA300 gravitational-wave experiment, which is achieving the highest sensitivity in the world at moment.
The newest program of NAOJ is VERA, in which 3 stations each with a 20m radio telescope are going to be constructed across the Japanese Islands. Each antenna has a bifocal receiver system, and the whole system should work as a phase-fluctuation-compensating VLBI system to measure the positions and motions of the master sources in the Milky Way with extremely high precision. This VLBI system should also support the moon mission SELENE to be launched by NASDA in 2004.