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We investigate the relation between the emission properties of supernova shock breakout in the circumstellar matter (CSM) and the behavior of the shock. Using a Monte-Carlo method, we examine how the light curve and spectrum depends on the asphericity of the shock and bulk-Compton scattering, and compare the results with the observed properties of X-ray outburst (XRO) 080109/SN 2008D. We found that the rise and decay time of the X-ray light curve do not significantly depend on the degree of shock asphericity and the viewing angle in a steady and spherically symmetric CSM. The observed X-light curve and spectrum of XRO 080109 can be reproduced by considering the shock with a radial velocity of 60% of the speed of light, and the wind mass loss rate is about 5 × 10−4M⊙.
RXJ 13434+0001 is a rare example of radio-quiet type-2 quasars at high redshift. It was discovered through deep ROSAT observations and identified with a galaxy with a strong but narrow Lyα emission line at z = 2.35. In order to constrain the hard-X-ray properties we observed RXJ 13434+0001 with ASCA. The main purpose is to study the origin of the X-ray emission observed with ROSAT. If it is a scattered component from a strongly absorbed AGN, we could see it much brighter in the hard X-ray band.
Seyfert galaxies often have extended emission line regions around their nucleus. We started an observation program of optical tridimensional spectroscopy for circumnuclear regions of nearby Seyfert galaxies to investigate the ionization source of the gas of just vicinity(typically several hundred pc) of nucleus.
Aoki et al. (1996) found outflowing gas in the Seyfert galaxy NGC 7319. The velocity of the outflow comes up to 500 km s−1 and its extent is 4 kpc. This outflow is one of the largest outflowing phenomenon that have ever been found in Seyfert galaxies. The radio emission found by van der Hulst & Rots (1981) aligns the outflowing gas. It suggests the radio emission has relation to the outflow. We have made higher resolution radio imaging of NGC 7319 with VLA to study in detail relation of radio emission to outflowing gas. These radio images have been compared to Hubble Space Telescope (HST) archival broad-band WFPC2 image. The systemic velocity 6740 km s−1 (Aoki et al. 1996) gives a distance of 90 Mpc for NGC 7319 assuming a Hubble constant H0=75 km s−1 Mpc−1. Thus 1″ corresponds to 450 pc.
A narrow-band imaging observation of the Seyfert galaxy NGC1068 was made in the Fabry-Perot mode of the Kyoto 3D Spectrograph attached to the 188cm telescope of the Okayama Astrophysical Observatory. We observed at wavelengths of Hα, [S ii]λ6716, [S ii]λ6731 and adjacent continua of the respective lines with a “tunable filter”, i.e. a gap-scanning etalon with a spectral resolution of 20 Å.
Tridimensional spectroscopy of the Seyfert 1 galaxy 3C 120 was carried out with Spectronebulagraph (SNG). We constructed a data cube which is free from atmospheric variations during the scans. We then separated the blended lines by deconvolving the line profiles, to obtain pure narrow-line images and narrow-line intensity ratio diagram.
The Kyoto 3-D Spectrograph was commissioned successfully at the 188-cm telescope of the Okayama Astrophysical Observatory in the spring of 1996. This instrument has four distinct modes (Ohtani et al. 1994): (1) narrow-band imager, which is an ordinary focal-reducer camera; (2) Spectro-NebulaGraph (long-slit spectrograph; Kosugi et al. 1995); (3) imaging Fabry-Perot interferometer, using either of two Fabry-Perot etalons from Queensgate Instruments (a tunable filter with R = 300 and another with R = 7000 for velocity-field observations. Broad-band (400–700 nm) coatings are deposited on both etalons. During observations, the etalon temperature is stabilized within 0.5°C); and (4) integral-field spectrograph of the TIGER-type (Bacon et al. 1995). In this mode, the spectra of 7 × 11 objects can be recorded simultaneously, along with 7 × 2 spectra of the sky 4′ away. The spatial resolution is 1″.3 and the field of view is 9″ × 14″.
We developed a slit-scanning type 3D-spectroscopic system named as Spectronebulagraph (hereafter SNG; Kosugi et al. 1994) at Okayama Astrophysical Observatory. A detailed description about SNG is presented by Ohtani et al. elsewhere in this colloquium. We present here the results of the 3D-spectroscopy of four nearby active galaxies by using SNG.
This nearby (at distance of 5.4 Mpc) Magellanic irregular galaxy has many H II regions in its main body suggesting violent star-formation activity. We performed tridimensional observations of NGC 4449 using SNG in order to obtain detailed kinematic structure and then to investigate the star-formation mechanism of NGC 4449. Hα intensity map, Hα velocity field are shown in figure 1. As is obvious in lower panel of figure 1, no global rotational motion was detected. Most impressive feature of the velocity field is kpc-scale mosaic structure of low velocity and high velocity components. Also, many filamentary components were newly found in 3D-datacube of the SNG observation.
The researches into extended emission line region (EELR) give us the valuable informations about the nucleus. A recent study of the EELR in the Seyfert 1 galaxy NGC 4151 by Yoshida and Ohtani (1993) have revealed that a strongly asymmetric radiation field in this typical Seyfert 1. They have suggested the anisotropy may be caused inside the BLR. It is important to examine if any other Seyfert 1 galaxy has an anisotropic nuclear radiation.
The famous Seyfert 1 galaxy NGC 3516 has EELR which extends ∼ 10” on either side of the nucleus. The morphology of the EELR is Z-shape. This nearby (D=38.9Mpc) galaxy is of type SBO for which the object is expected to be free from contamination by HII regions and dust clouds.
A multi-hierarchy simulation model aiming magnetic reconnection studies is developed and improved in which macroscopic and microscopic physics are computed consistently and simultaneously. Macroscopic physics is solved by mag-netohydrodynamics (MHD) algorithm, while microscopic dynamics is expressed by particle-in-cell (PIC) algorithm. The multi-hierarchy model relies on the domain decomposition method, and macro- and micro-hierarchies are interlocked smoothly by hand-shake scheme. As examination, plasma flow injection is simulated in the multi-hierarchy model. It is observed that plasmas flow from a macro-hierarchy to a micro-hierarchy across the magnetic field smoothly and continuously.
Piezoresponse measurements using scanning probe microscopy (SPM) were performed for island structures at the initial growth stage of Pb(Zr,Ti)O3 (PZT) (Zr/Ti=0/100, 24/76 and 74/26) thin films prepared by metalorganic chemical vapor deposition(MOCVD). Deposition times were varied from 5s to 7min to control the size of PZT islands. When deposition times were shorter than 3min, (111)-oriented triangular-shaped PZT islands were observed before forming a continuous film. The width and height of PZT islands deposited at 3min were 160 and 70nm for Zr/Ti = 0/100, 100 and 30nm for Zr/Ti = 24/76, and 80 and 20nm for Zr/Ti = 74/26, respectively. The size of islands decreased with increasing the Zr composition. Hysteresis loops due to polarization switching were observed in the phase difference and displacement of piezoresponse measured using scanning probe microscopy (SPM). This result proves that nano-size PZT islands have weak ferroelectricity. The minimum width and height of PZT islands which showed ferroelectricity were 70 and 30nm for Zr/Ti=24/76.
Thin films of Y-type magnetoplumbite (Ba2Co2Fe12O22: Co2Y) with such a huge unit cell length as 43.5 Å has been successfully fabricated for the first time with the aid of combinatorial optimization of pulsed laser deposition process. Planning a thickness gradient CoO buffer layer on MgAl2O4(111) substrate was very effective for prevent the phase separation of Co deficient impurity (BaFe2O4) to reside in the formation of desired Co2Y phase.From the TEM analysis, the CoO buffer layer of optimum thickness was incorporated into the Co2Y film to make theinterface with the make an atomically sharp.
We report on the development of a high throughput x-ray diffractometer that concurrently measures spatially resolved x-ray diffraction (XRD) spectra of epitaxial thin films integrated on a substrate. A convergent x-ray is focused into a stripe on a substrate and the diffracted beam is detected with a two-dimensional x-ray detector, so that the snapshot image represents a mapping of XRD intensity with the axes of the diffraction angle and the position in the sample. High throughput characterization of crystalline structure is carried out for a BaxSr1-xTiO3 composition-spread film on a SrTiO3 substrate. Not only the continuous spread of the composition (x), but also the continuous spread of the growth temperature (T) are given to the film by employing a special heating method. The boundary between the strained lattice and relaxed lattice is visualized by the concurrent XRD as functions of x and T in a high throughput fashion.
We have investigated the formation and current-voltage characteristics of Si-dots/SiC multilayer heterostructures on p+Si(100) substrates by means of supersonic free-jet chemical vapor deposition using a single gas source CH3SiH3. Si-dots were successfully deposited on epitaxial SiC thin films on Si(100) with assistance of a tungsten hot filament. Negative deferential resistance was observed in the current-voltage curve of SiC/Si-dot/SiC measured by an atomic force microscope using a gold-coated conductive cantilever. The observed current-voltage characteristics can be attributed to the hole resonant tunneling through the SiC double barriers.
Chemical mechanical polishing is an essential process for achieving a high degree of planarization. The planarity after CMP sensitively depends on pattern scales, pattern densities and mechanical properties of polishing pads. In order to simulate the topography after CMP, a numerical model for the polishing pad is proposed. In this model, the surface roughness layer of the polishing pad is assumed as a flat soft layer. The distribution of the contact pressure between the patterned wafer and the polishing pad is calculated with finite element method, and the pattern topography is modified based on the pressure dependency of the polishing rate. The iterations of the contact pressure analyses and the topography modifications give the progress of the polishing process numerically. The model is applied to oxide CMP process with silica slurry and stacked pad of polyurethane and non-woven fabric. The compressive elastic moduli of polyurethane layer and non-woven fabric layer are measured dynamically. The elastic modulus of the soft layer is treated as a fitting parameter between the experimental results and the numerical model. The models with the elastic modulus of 10 MPa for the soft layer show good agreements with the experimental results in both of a short range, where the compressive deformation of the pad is dominant, and a long range, where the bending deformation is dominant. Static measurements for the surface elasticity of the polyurethane layer also give a good agreement with the model. The proposed pad model should be useful for the topography simulation, and it also guides the development of new polishing pads.
GaAs epilayers on (100)Si substrates have been grown by ionized cluster beam(ICB) method under conventional high vacuum conditions. The developed deposition method has two characteristics: first is cleaning the Si surface by accelerated As clusters and second is adopting double layer structure in order to confine dislocations within a primary layer. As a result of these features, the etch pit density came to be 2×1O6cm−2 and the crystal quality was comparable to that of molecular beam epitaxy(MBE) or metal organic chemical vapor deposition(MOCVD) method. In the present paper, we discuss those characteristic phenomena of ICB method and demonstrate MESFET's fabricated on our GaAs grown on Si substrates.
We have investigated the structural properties of sputter deposited granular AU-Al2O3 films. The films exhibit an abrupt percolation transition from insulating to metallic behavior at the composition of xc-40 vol.% Au. STM measurements yield images of individual grains and clusters of grains consistent with the TEM images. The surface roughness increases abruptly from 30Å to 50Å as the Au concentration increases from 35 to 45 vol.%. The roughening of the films in the metallic regime is consistent with behavior of the X-ray reflectivity.
High quality crystalline γ -Al2O3 films were epitaxially grown on Si(111) substrates at growth temperatures from 750 to 900°C by molecular beam epitaxy using an Al solid source and N2O gas. Very thin γ -Al2O3 films grown at a growth temperature of 850°C showed streaky reflection high-energy electron diffraction patterns. By in situ x-ray photoelectron spectroscopy measurements, carbon contamination, as is seen in the films grown with a Al(CH3)3 source, was not detected within the measurement sensitivity. The stoichiometry of the grown film was found to be similar to that of Al2O3. Growth rates of epitaxial γ -Al2O3 layers decreased with increasing growth temperatures. The predominant growth of the γ -Al2O3(111) crystal orientation was confirmed on Si(110) and Si(100) substrates.
Ruthenium dioxide (RuO2) thin films are evaluated as bottom electrode for dielectric SrTiO3. It was found that a RuO2 (50nm) / Ru (20nm) barrier layer on a Si substrate is effective as an oxygen barrier layer and as a metal diffusion barrier layer for sputter deposited SrTiO3 films at substrate temperature of 450°C. To test suitability for high temperature processes, RuO2/Ru electrodes were annealed in air at 600°C. 100nm-thiick RuO2 was sufficient to prevent oxygen diffusion. After annealing in the same condition, the leakage current of sputter deposited SrTiO3 (150nm) on RuO2(50nm) / Ru(50nm) was 7.6 × 10 −9 (A/cm2) at 2V.
A hard X-ray microbeam with submicrometer spot size from synchrotron radiation (SR) sources is expected to add a new dimension to various X-ray analysis methods. A Fresnel zone plate (FZP) is one of the promising focusing elements for X-rays. In order to develop high performance multilayer FZP for use in the hard X-ray region, Cu/Al concentric multilayers were fabricated by use of a DC sputtering deposition process. Lower Ar gas pressure or higher rotating speed of a wire substrate has been effective in forming smoother multilayer interfaces. From a focusing test of the Cu/Al FZP (100-zones) by the SR (λ= 0.154nm), microbeams of 1.5 μm φ and 0.8 μm φ have been achieved for the first- and third-order focal beams, respectively.