The Hyper Suprime-Cam (HSC) is an 870 megapixel prime focus optical imaging camera for the 8.2 m Subaru telescope. The wide-field corrector delivers sharp images of 0${^{\prime\prime}_{.}}$2 (FWHM) in the HSC-i band over the entire 1${^{\circ}_{.}}$5 diameter field of view. The collimation of the camera with respect to the optical axis of the primary mirror is done with hexapod actuators, the mechanical accuracy of which is a few microns. Analysis of the remaining wavefront error in off-focus stellar images reveals that the collimation of the optical components meets design specifications. While there is a flexure of mechanical components, it also is within the design specification. As a result, the camera achieves its seeing-limited imaging on Maunakea during most of the time; the median seeing over several years of observing is 0${^{\prime\prime}_{.}}$67 (FWHM) in the i band. The sensors use p-channel, fully depleted CCDs of 200 μm thickness (2048 × 4176 15 μm square pixels) and we employ 116 of them to pave the 50 cm diameter focal plane. The minimum interval between exposures is 34 s, including the time to read out arrays, to transfer data to the control computer, and to save them to the hard drive. HSC on Subaru uniquely features a combination of a large aperture, a wide field of view, sharp images and a high sensitivity especially at longer wavelengths, which makes the HSC one of the most powerful observing facilities in the world.

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The crystal structure and magnetic properties of 6H-perovskites Ba 3 MSb 2 O 9 (M = Mn, Co, and Ni) were investigated. The M = Co and Ni compounds have a hexagonal structure with space group P6 3 /mmc, while the Mn compound has a monoclinically distorted structure with space group C2/c. From the results of magnetic susceptibility and specific heat measurements, it was found that they show an antiferromagnetic transition at 10.0 K (for M = Mn), 3.8 K (Co) and 13.5 K (Ni), and the onset of the magnetic transition was observed much above T N . The powder neutron diffraction measurements for Mn and Co compounds were carried out, and their magnetic structures were determined. Both compounds adopt the non-collinear 120 • structure in the ab-plane. These magnetic properties show the existence of a geometric magnetic frustration derived from the triangular array of magnetic M ions in the ab-plane.

The crystal structures and magnetic properties of quaternary oxides Ba 3 LnIr 2 O 9 (Ln = Y, lanthanides) are reported. Rietveld analyses of their x-ray diffraction data indicate that they adopt the 6H-perovskite-type structure with space group P6 3 /mmc or, in the case of Ln = La and Nd only, a monoclinically distorted structure with space group C2/c. They have the valence state of Ba 3 Ln 4+ Ir 4+ 2 O 9 (for Ln = Ce, Pr, and Tb) or Ba 3 Ln 3+ Ir 4.5+2 O 9 (for Ln = Y and other lanthanides). Measurements of the magnetic susceptibility and specific heat were carried out for Ln = Y, Ce, Pr, Tb, and Lu. It was found that the effective magnetic moment of Ir ions is significantly small, which indicates the existence of the strong antiferromagnetic interaction between Ir ions in the Ir 2 O 9 bioctahedra. The Y and Lu compounds with an unpaired magnetic moment remaining in the Ir 4.5+2 O 9 show an antiferromagnetic transition at 4.0 and 5.1 K, respectively. For Ba 3 TbIr 2 O 9 , a long-range magnetic ordering of Tb 4+ ions was found at 2.0 K.

The perovskite-type compounds Sr2LnRuO6 (Ln = Eu-Lu) have been synthesized, and their crystal structures and magnetic properties have been investigated. Powder x-ray diffraction measurements and the Rietveld analysis show that they are monoclinic with space group P21/n and that Ln3+ and Ru5+ ions are structurally ordered. These compounds show complex magnetic transitions at low temperatures. These transitions are considered to be antiferromagnetic ones from large negative Weiss constants. Below the transition temperatures, there is a large difference in the temperature dependence of the magnetic susceptibility measured under the zero-field cooled condition and under the field cooled condition, which shows the existence of a weak ferromagnetic moment associated with the antiferromagnetism.

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The central region of the Seyfert 2 galaxy NGC 1068 is imaged in the mid infrared (MIR) using the Mid-Infrared Test Observation System on the 8.2 m Subaru Telescope. The oversampling pixel scale associated with shift-and-add method shows 0 ′′ .1 resolution images with a high dynamic range after deconvolution. Along with an extended structure at a position angle (P.A.) of −10 • with higher surface brightness, another structure extends wider with lower surface brightness at a P.A. of 20 • . The central peak elongates north-south with FWHM of 0 ′′ .3 × 0 ′′ .2. Spectral energy distribution (SED) of the central peak is fitted to have the silicate absorption feature of τ 9.7µm = 0.9 ± 0.3. This is half of the absorption expected from the near-infrared (NIR) feature of carbonaceous dust. This suggests a temperature gradient of the absorbing dust along the line of sight. Another possibility, which is not distinguishable here, is the size distribution of dust different from our Galaxy. Intrinsic luminosity of emission from the central peak is 3 × 10 37 W. The SED shows a hint of the poly aromatic hydrocarbon (PAH) emission features. Although a high spatial resolution MIR spectrum is required, it suggests that the PAH carriers near the active galactic nuclei (AGNs) are sheltered from the high-energy emission from the AGNs and the AGNs have nuclear starbursts. For the NIR disklike structures, no counterparts are detected in the MIR. The nature of the structures remains unclear.

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