For future space IR missions, such as SPICA, it is crucial to establish an experimental method for eval- uating the performance of mid-IR detectors. In particular, the wavelength dependence of the sensitivity is important but difficult to be measured properly. We are now preparing a testing system for mid-IR Si:As/Si:Sb detectors on SPICA. We have designed a cryogenic optical system in which IR signal light from a pinhole is collimated, passed through an optical filter, and focused onto a detector. With this system, we can measure the photoresponse of the detector for various IR light using optical lters with different wavelength properties. We have fabricated aluminum mirrors which are adopted to minimize thermal distortion effects and evaluated the surface figure errors. The total wavefront error of the optical system is 1.3 μm RMS, which is small enough for the target wavelengths (20-37 μm) of SPICA. The point spread function measured at a room temperature is consistent with that predicted by the simulation. We report the optical performance of the system at cryogenic temperatures.

We built a 8 μm selected sample of galaxies in the NEP-AKARI eld by defining 4 redshift bins with the four AKARI bands at 11, 15, 18 and 24 microns (0:15 < z < 0:49, 0:75 < z < 1:34, 1:34 < z < 1:7 and 1:7 < z < 2:05) . Our sample contains 4079 sources, 599 are securely detected with Herschel/PACS. Also adding ultraviolet (UV) data from GALEX, we fit the spectral energy distributions using the physically motivated code CIGALE to extract the star formation rate, stellar mass, dust attenuation and the AGN contribution to the total infrared luminosity (LIR). We discuss the impact of the adopted attenuation curve and that of the wavelength coverage to estimate these physical parameters. We focus on galaxies with a luminosity close the characteristic L* IR in the different redshift bins to study the evolution with redshift of the dust attenuation in these galaxies.

The AKARI NEP Deep Field Survey is an international multiwavelength survey over 0.4 deg2 of the sky. This is the deepest survey made by the InfraRed Camera (IRC) of the infrared astronomical satellite AKARI with 9 filters continuously covering the 2-25 μm range, including three filters in the Spitzer gap between the IRAC and MIPS coverages. This enabled us to make sensitive MIR detection of AGN candidates at z~ 1, based on hot dust emission in the AGN torus. It is also eficient in detecting highly obscured Compton-thick AGN population. In this article, we report the rst results of X-ray observations on this eld. The field was covered by 15 overlapping Chandra ACIS-I observations with a total exposure of ~300 ks, detecting  450 X-ray sources. We utilize rest-frame stacking analysis of the MIR AGN candidates that are not detected individually. Our preliminary analysis shows a marginal detection of the rest-frame stacked Fe Kα line from our strong Compton-thick candidates.

We report a search for fluctuations of the sky brightness toward the North Ecliptic Pole with AKARI, at 2.4, 3.2, and 4.1 μm . The stacked images with a diameter of 10 arcminutes of the AKARI-Monitor Field show a spatial structure on the scale of a few hundred arcseconds. A power spectrum analysis shows that there is a significant excess fluctuation at angular scales larger than 100 arcseconds that cannot be explained by zodiacal light, diffuse Galactic light, shot noise of faint galaxies, or clustering of low-redshift galaxies. These findings indicate that the detected fluctuation could be attributed to the first stars of the universe, i.e., Population III stars.

The 21st Century Frontier Program, which is one of the R&D programs funded by Korean government, was launched in 1999 to elevate the status of Korean science and engineering capabilities to the advanced nation in the strategic fields. Currently, 23 different fields of science and engineering programs are carried out by researchers in institutes, universities and industries. Center for Advanced Materials Processing (CAMP) was formulated in 2001 to develop the advanced materials as well as to improve the parts manufacturing process. The main role of CAMP is proposing and forecasting the long term vision in Materials Processing Technology and also supporting the project teams for their best performance in R&D. The CAMP program consists of 5 research areas such as, Multi-layer Ceramic Electronic Parts, Powder Formed Precision Parts, 3 Dimensional Polymer Based Composites, Functional Metal Sheets, Parts Integration Technology. An introduction of R & D activities at CAMP, specially focusing on powder metallurgy, wil be presented.

Metal powder for dust core application was developed. The powder can be produced improved high-pressure water atomization process. The process has produced powder of spherical shape and lower coercivity. The dust core obta ined shows lower core loss.

Co-based amorphous powder was produced by a new atomization process “Spinning Water Atomization Process (SWAP)”, having rapid super-cooling rate. The composition of the alloys was ((Co0.95Fe0.05)1-xCrx)75Si15B10 (x=0, 0.025, 0.05, 0.075). The powders became the amorphous state even if particle size was up to about 500 μm. The coercive force of powders was about 0.35 - 0.7 Oe. Furthermore, Co-based amorphous powder cores with glass binders were made by cold-pressing and sintering methods. The initial permeability of the core in the frequency range up to 100 kHz was about 110, and the core loss at 100 kHz for Bm = 0.1 T was 350 kW/m3.

Clusters of galaxies are filled with X-ray emitted hot gas with the temperature of T ${\~}$ 수식 이미지2-10 keV. Recent X-ray observations have been revealing unexpectedly that many cluster cores have complicated, peculiar X-ray structures, which imply dynamical motion of the hot gas. Moreover, X-ray spectra indicate that radiative cooling of the cool gas is suppressed by unknown heating mechanisms (the 'cooling flow problem'). Here we propose a novel mechanism reproducing both the inhomogeneous structures and dynamics of the hot gas in the cluster cores, based on state-of-the-art hydrodynamic simulations. We showed that acoustic-gravity waves, which are naturally expected during the process of hierarchical structure formation of the universe, surge in the X-ray hot gas, causing a serous impact on the core. This reminds us of tsunamis on the ocean surging into an distant island. We found that the waves create fully-developed, stable turbulence, which reproduces the complicated structures in the core. Moreover, if the wave amplitude is large enough, they can suppress the cooling of the core. The turbulence could be detected in near-future space X-ray missions such as ASTRO-E2.