We present a deep K 0 -band (2.12 m) imaging of the 1 0 ; 1 0 Subaru Super Deep Field (SSDF) taken with the Subaru adaptive optics (AO) system. Total integration time of 26.8 hr results in the limiting magnitude of K 0 $ 24:7 (5 , 0B2 aperture) for point sources and K 0 $ 23:5 (5 , 0B6 aperture) for galaxies, which is the deepest limit ever achieved in the K 0 band. The average stellar full width at half-maximum (FWHM) of the co-added image is 0B18. Based on the photometric measurements of detected galaxies, we obtained the differential galaxy number counts, for the first time, down to K 0 $ 25, which is more than 0.5 mag deeper than the previous data. We found that the number count slope d log N /dm is about 0.15 at 22 < K 0 < 25, which is flatter than the previous data. Therefore, detected galaxies in the SSDF have only negligible contribution to the near-infrared extragalactic background light (EBL), and the discrepancy claimed so far between the diffuse EBL measurements and the estimated EBL from galaxy count integration has become more serious. The size distribution of detected galaxies was obtained down to the area size of less than 0.1 arcsec 2 , which is less than half of that of the previous data in the K 0 band. We compared the observed size-magnitude relation with a simple pure luminosity evolution model allowing for intrinsic size evolution and found that a model with no size evolution gives the best fit to the data. It implies that the surface brightness of galaxies at high redshift is not much different from that expected from the size-luminosity relation of present-day galaxies.

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A genome-wide scan for a locus responsible for exploratory eye movement (EEM), which is quantitative and can be disturbed in association with schizophrenia, was performed. A 10-cM resolution genome-wide linkage analysis of the EEM disturbance with 358 highly polymorphic microsatellite markers in 38 nuclear families with 122 members (38 probands, 47 sibs, and 37 parents) including 58 sib-pairs yielded the suggestive linkage to the GCT10C10 marker on chromosome 22q11.2 (LOD = 2.48). Dense mapping with additional markers around the GCT10C10 marker yielded evidence for significant linkage between EEM disturbance and markers D22S429 and D22S310 on chromosome 22q12.1 (LOD score of 4.63) with suggestive evidence for the chromosome region 22q11.2-q12.1. Our findings suggest that a relatively small number of loci may control the schizophrenia-related quantitative EEM trait. We believe that identifying gene(s) on chromosome 22q associated with the EEM phenotype may forward our understanding of the etiology of schizophrenia.

The design and performance of the Cassegrain Adaptive Optics (AO) system for the 8.2 m Subaru Telescope are reported. The system is based on a curvature wavefront sensor with 36 photon-counting avalanche photodiode modules and a bimorph wavefront correcting deformable mirror with 36 driving electrodes. The engineering first light of the AO system took place in 2000 December. The AO system has been in service since 2002 April for two open-use instruments, an infrared camera and spectrograph and a coronagraph imager with adaptive optics. The Strehl ratio in the K-band is around 0.3 for bright guide stars under 0. 4 K-band seeing condition. The control loop performs with 2060 corrections per second. High sensitivity of the wavefront sensor allows significant improvement in the image quality, even for faint guide stars down to R = 18 mag. The FWHM of stellar images in a globular cluster was measured to derive an estimation of the isoplanatic angle and was found nearly constant out to 30 from the guide star, indicating that the height of the effective turbulent layer of that particular night was less than 1.8 km. The ongoing upgrade plans for a fivefold increase in the number of control elements and for the installation of a laser guide AO system are described.