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We have carried out wide field imaging observations in the near-infrared (J, H and K′ band) with a large format array camera attached to the prime focus of the 105 cm Schmidt telescope at Kiso Observatory. The image resolution, limiting magnitudes and the effect of thermal radiation are discussed.
We present the results of wide-field imaging of nearby galaxies observed in the near-infrared using a large format array. The total magnitudes and mass-to-luminosity ratios of NGC 253, M 82, NGC 891, and some cluster members are discussed.
The region south of the reflection nebula NGC1333 in Perseus is an active star forming region including numerous Herbig-Haro objects and at least 5 protostar candidates with molecular outflows and far-infrared emission. It has been actively studied in various wave bands (e.g. Aspin et al 1994 and references therein). We observed this region with ASCA with the primary objective to detect X-rays from the protostars embedded deep in the molecular cloud.
Near-infrared (NIR) emission in galaxies is mainly radiated by old population low temperature stars, which construct the basic stellar structure and keep the trails of past galaxy evolution. On the other hand, optical observations show recent star formation activity, especially in spiral galaxies. Therefore multi-color observations from optical to near-infrared wavelengths are very important to understand the past and recent star-formation history. Nearby large galaxies are well studied not only in optical but also in mid- and far-infrared by IRAS, CO and HI radio observations. However, the study in the near-infrared is still limited because large format arrays are not common. Here we show a wide-field, near-infrared imaging of nearby elliptical and spiral galaxies and discuss their star-formation history.
Sofue (1996, 1997) presented accurate rotation curves of nearby galaxies, which are almost completely sampled from the inner to outer regions. The conspicuous common feature of the rotation curves is a steep rise at the inner bulge. The rise suggests a compact massive concentration near the nucleus (Sofue 1996). The study of the light distribution at the inner bulge demands accurate surface photometry at near-infrared wavelengths, where dust extinction is much less effective than in the optical. Most of Sofue's samples are nearby large galaxies, so that observations with a wide field view is clue to constructing reliable light distribution models.
We report on the spectral and temporal properties of the 50 ms pulsar PSR B0540–69 using ASCA archival data obtained during 1993 to 1995. From the spectral analysis it was found that the spectra of the whole (nebular and pulsed) emission and pulsed emission in the range 1-10 keV can be represented by a single power law of photon index, Γ = 2.00 ± 0.02 and Γpulsed = 1.7 ± 0.3 respectively. The parameters for pulse frequency change during 1993-1995 were obtained using the 9 pulse frequency measurements with ASCA. The parameters derived from the ASCA observations are consistent with the previous measurements, suggesting high stability of this pulsar, ΔΩ/Ω ≲ 0.5 × 10−7 over the past 10 years. These results confirm similarity of this pulsar with the Crab pulsar.
We have carried out imaging observations in the near-infrared (J, H and K’ band) with a large format array camera attached to the prime focus of the 105 cm Schmidt telescope at Kiso Observatory. The image resolution, limiting magnitudes and effect of thermal radiation are presented, based on observations of nearby galaxies. Considering the results, we are constructing a new larger near-infrared camera optimized for use with the Kiso Schmidt.
Most of the neutron star cooling calculations with the only exception of Malone's (1974) have assumed an isothermal stellar core. Here we report on a neutron star cooling calculation which makes full use of the stellar evolution code and the recent thermal conductivity calculations by Flowers and Itoh (1976, 1979).
The enhancement factor for the rate of thermonuclear reactions which involve two kinds of nuclei with charges Zi and Zj in the strong-screening regime is given for general cases of surrounding nuclear plasmas by the formula, exp[1.25Γij −0.095τij(3Γij/τij)2]. Here, Γij = 2ZiZje2/(ai+aj)T; ai = [3Zi/4πΣkZknk]1/3; τij = [(27π2/4)(2μijZi2Zj2e4Th2)]1/3; μij is the reduced mass for the two reacting nuclei Zi and Zj; and nk is the number density of nuclei Zk. The calculation is based on the recent results of Monte Carlo computations for binary ion mixtures, which have shown that the screening functions hij(r) at intermediate distances [0.5 ≤ r/[(ai+aj)/2] ≤ 1.6] can be expressed to a good degree of accuracy by
Application to the calculation of carbon ignition in the carbon-oxygen core of a highly evolved star is discussed. The carbon ignition temperature is found to be single-valued as a function of the density in contrast to the work of Graboske.
There are serious discrepancies among some of the recent neutron star cooling calculations by various groups. We have been investigating the possible source of these discrepancies. In this paper, we report our findings. We also report the preliminary result of our most recent cooling calculations without assuming an isothermal stellar evolution code. In this work, we used the currently existing best energy transport theories, as well as general relativity, both in thermodynamics and hydrodynamics.
We have a plan to a radioastronomy mission at the Moon. This is dedicated to the mapping of the CBR anisotropy in order to study the properties of the early Universe, especially galaxy formation. This is a candidate for the Moon mission of NASDA, launched by an HIIA Rocket. The mission carries an 1.5 m (min.) offset parabola antenna with radiation shield to the north polar region of the Moon. This will observe CBR anisotropy at three (min.) frequencies between 30 to 90 GHz. The angular resolution is 9’ at 90 GHz. The telescope will observe the donut-shaped sky between 5 to 30 degree (not fixed) from the Moon celestial north pole. The resultant sensitivity will reach ΔT/T ⋍ 106K in 30’x30’ pixel and ΔT/T ⋍ 105K in 9’x9’ pixel.
We have fabricated Bi2212 and Bi2223 bulk samples by shock compaction technique. Seed crystals were added to the starting materials in order to promote crystallization. The grain size of the prepared sample was increased by the addition of seed crystals to the starting material.
In this paper, an analysis of the high voltage induced degradation in top gate amorphous silicon Thin Film Transistors (TFT) will be shown, including the aspect of self-heating. It will be shown through experimental results that the degradation level under high voltages on drain and gate is different for TFT's with different channel lengths. In addition, the temperature distribution over the TFT area for devices with different channel length is simulated. Simulation shows that the peak of temperature distribution is located at the drain/channel edge and that level of thermal heating depends on the channel length.
The field emission properties of hydrogenated amorphous carbon containing up to 29at% nitrogen (a-C:N:H), grown in an integrated distributed electron cyclotron resonance (IDECR) reactor were studied using a sphere-plane geometry. All films were smooth in character and required a high field (20-70V/νm) activation process before emission, which created micron- sized craters in the emission region. Further analysis suggested that the emission originates from activation-created geometrically enhanced areas around the crater region. Upon low-level nitrogen incorporation (N/N+C≤0.2), the field required for activation decreased from 54V/νm to a minimum value of 20V/νm. The turn-on field required for 1νA of current also decreased, reaching a minimum of 11.3V/νm. The decrease in activation and turn-on field was related to the increase in conductivity observed with increasing nitrogen content. At higher nitrogen concentrations, the increase in activation energy and turn on field for emission may be due to changes in overall material structure, as indicated by the decreasing optical gap
A new structure of triode type field emission displays based on single-walled carbon nanotube emitters is demonstrated. In this structure, gate electrodes are situated under cathode electrodes with an in-between insulating layer, so called under-gate type triode. Electron emission from the carbon nanotube emitters is modulated by changing gate voltages. A threshold voltage is approximately 70 V at the anode bias of 275 V.
Recently, there has been considerable interest in electronic device applications of diamond thin films. The chemical properties of diamond is stable. So diamond thin films become very useful if they are used for electronic devices. We consider diamond thin films as blue like emitting devices because diamond has a wide band gap(about 5.5eV). Some light emitting devices have been known . First of all we have been trying to deposit diamond thin films on the large areas. If they deposit on the large areas, light emitting devices may be massproduced.
The reliability of the a-Si drum has been investigated via environmental tests and durability copy testing, and its electrophotographic properties have been confirmed to be very stable. Regarding imaging properties, a-SiC surface layer plays an important part suppressing the noise within the image. It has been discovered that the blurring of the image in high humidity after many copying cycles is caused by the deterioration of the surface layer which occurs through exposure to corona discharge. This blurring is eliminated by preventing absorption of moisture at the surface, such as heating the drum. In this manner, it has been observed that a-Si drum maintains a high quality image up to 1,000,000 copy sheets.
The dopant segregation at the polycrystalline silicon grain boundaries in device fabrication processes has been studied with a new approach using spreading resistance(SR) measurement, SIMS and cross-sectional TEM(XTEM). Phosphorus implanted LPCVD poly-Si films were annealed at 900°C-1000°C in N2 for 30min. Electrically active dopant concentrations obtained from SR measurements are constant in depth within the poly-Si films. On the other hand, the phosphorus concentration measured by SIMS is found to increase with increasing depth and to have linear relationships to reciprocal grain sizes observed by XTEM for all poly-Si films. The linear relationship indicates that the number of segregated phosphorus atoms per unit grain surface area at the grain boundaries is uniform throughout poly-Si films. Both phosphorus concentrations in the grains and at the grain boundaries are evaluated. The heat of segregation of 1.7eV is obtained from the annealing temperature dependence of the segregation ratio. Our results indicate that carrier concentration in the poly-Si film is more sensitive to annealing temperature in device fabrication processes. The carries concentration is determined by kinetics rather than by equilibrium segregation of dopants.
We have studied the reactions which occur in metal-metalloid multilayers made from elements which have binary eutectic phase diagrams. The metal mediates crystallization of the amorphous as-deposited metalloid by crystal nucleation inside the metal layer followed by rapid diffusion through the metal from amorphous to crystalline phases. The metalloid crystallization temperature is significantly reduced by this reaction. Systems showing this behavior are Al-Si, Ag-Si, Ag-Ge, Co-C, Ni-C and Fe-C. We believe, therefore, that it is a general phenomenon which we have now extended to the case of Ag-SiC.