Discovery of Crystallized Water Ice in a Silhouette Disk in the M43 Region

We present the 1.9--4.2um spectra of the five bright (L<11.2) young stars associated with silhouette disks with moderate to high inclination angle of 39--80deg in the M42 and M43 regions. The water ice absorption is seen toward d121-1925 and d216-0939, while the spectra of d182-316, d183-405, and d218-354 show no water ice feature around 3.1um within the detection limits. By comparing the water ice features toward nearby stars, we find that the water ice absorption toward d121-1925 and d216-0939 most likely originates from the foreground material and the surrounding disk, respectively. The angle of the disk inclination is found to be mainly responsible for the difference of the optical depth of the water ice among the five young stars. Our results suggest that there is a critical inclination angle between 65deg and 75deg for the circumstellar disk where the water ice absorption becomes strong. The average density at the disk surface of d216-0939 was found to be 6.38x10^(-18) g cm^(-3). The water ice absorption band in the d216-0939 disk is remarkable in that the maximum optical depth of the water ice band is at a longer wavelength than detected before. It indicates that the primary carrier of the feature is purely crystallized water ice at the surface of the d216-0939 disk with characteristic size of ~0.8um, which suggests grain growth. This is the first direct detection of purely crystallized water ice in a silhouette disk.Comment: 28 pages, 8 figures, Accepted by Ap

Financial integration in East Asia

This paper examines the degree of integration into world financial markets and the impacts on several key macroeconomic variables of selected East Asian economies, and draws policy implications. According to our analysis, the degrees of integration into world financial markets in those economies are increasing. Regarding the impacts of increasing integration into world financial markets on several macroeconomic variables, we find three results. First, casual two-way plots among macroeconomic variables do not support the theoretical prediction of reduction in relative consumption volatility. Second, the saving-investment correlation is higher than those of in Euro area economies. Third, the degrees of smoothing of idiosyncratic shock by cross-holding of financial assets are lower than Euro area economies. Those results suggest two policy implications. First, there's some room for improvement in welfare gains in those economies by further risk sharing. Second, holding all other conditions given, the increasing integration into world financial markets alone is unlikely to provide a sound ground for a currency union in East Asia at this stage.

Financial Integration in East Asia

This paper examines the degree of integration into world financial markets and the impacts on several key macroeconomic variables of selected East Asian economies, and draws policy implications. According to our analysis, the degrees of integration into world financial markets in those economies are increasing. Regarding the impacts of increasing integration into world financial markets on several macroeconomic variables, we find three results. First, casual two-way plots among macroeconomic variables do not support the theoretical prediction of reduction in relative consumption volatility. Second, the saving-investment correlation is higher than those of the euro area economies. Third, the degrees of smoothing of idiosyncratic shock by cross-holding of financial assets are lower than the euro area economies. These results suggest two policy implications. First, there is some room for improvement in welfare gains in those economies by means of further risk sharing. Second, holding all other conditions equal, the increasing integration into world financial markets alone is unlikely to provide a sound ground for a currency union in East Asia at this stage.Exchange rate regime, financial integration, risk sharing

Anomalous Fermi level behavior in GaMnAs at the onset of ferromagnetism

We present the systematic study of the resonant tunneling spectroscopy on a series of ferromagnetic-semiconductor Ga1-xMnxAs with the Mn content x from ~0.01 to 3.2%. The Fermi level of Ga1-xMnxAs exists in the band gap in the whole x region. The Fermi level is closest to the valence band (VB) at x=1.0% corresponding to the onset of ferromagnetism near the metal-insulator transition (MIT), but it moves away from the VB as x increasing or decreasing from 1.0%. This anomalous behavior of the Fermi level indicates that the ferromagnetism and MIT emerge in the Mn-derived impurity band.Comment: 4 pages, 4 figures, 1 table (minor revision

Building E-Service Systems:From Planning to Implementation

For building e-service systems, this paper discusses the difference between traditional system integration and e-service system integration. First, e-service systems should be planed by more than two companies who have different core competences. Second, project manager who builds an e-service system should integrate not only hardware nor software but also digital contents. Third, e-service systems are developed not for cost reduction but for customers’ satisfaction. Paying attention to these points, this paper presents components, risks, building procedure, and office role for building e-service systems, and reviews our experiences

MgII Absorption Lines in z=2.974 Damped Lyman-alpha System toward Gravitationally Lensed QSO APM 08279+5255: Detection of Small-scale Structure in MgII Absorbing Clouds

1.02-1.16 micron spectra (R ~ 7,000) of the gravitationally lensed QSO APM 08279+5255 at z_em=3.911 were obtained during the commissioning run of IRCS, the 1-5 micron near-infrared camera and spectrograph for the Subaru 8.2 m Telescope. Strong MgII doublet at 2976,2800 angstrom and FeII (2600 angstrom), FeII (2587 angstrom) absorption lines at z_abs=2.974 were clearly detected in the rest-frame UV spectra, confirming the presence of a damped Lyman-alpha system at the redshift as suggested by Petitjean et al. Also MgI (2853 angstrom) absorption line is probably detected. An analysis of the absorption lines including velocity decomposition was performed. This is a first detailed study of MgII absorption system at high redshift (z > 2.5) where the MgII doublet shifts into the near-infrared in the observer's frame. The spectra of the lensed QSO pair A and B with 0.38 arcsec separation were resolved in some exposure frames under excellent seeing condition. We extracted the MgII doublet spectra of A and B separately. Although three velocity components (v ~ -28, +5, +45 km/s) are known to exist in this MgII system (Petitjean et al.), the v ~ +45 km/s absorption line was not detected toward source B, showing that the +45 km/s MgII cloud lies only in the line of sight to the source A. Our results suggests that the size of the MgII absorbing clouds is as small as 200 pc, which corresponds to the separation of A and B at the redshift of the absorber. This is the first direct detection of the small-scale structure of MgII clouds at high-redshift, confirming the estimated cloud sizes from photoionization model by Churchill and Charlton.Comment: ApJ in press (Vol.569, 20 April 2002 issue

Enhancement of Terrestrial Diffuse X-ray Emission Associated With Coronal Mass Ejection and Geomagnetic Storm

We present an analysis of a Suzaku observation taken during the geomagnetic storm of 2005 August 23-24. We found time variation of diffuse soft X-ray emission when a coronal mass ejection hit Earth and caused a geomagnetic storm. The diffuse emission consists of fluorescent scattering of solar X-rays and exospheric solarwind charge exchange. The former is characterized by a neutral oxygen emission line due to strong heating of the upper atmosphere during the storm time, while the latter is dominated by a sum of C V, C VI, N VI, N VII, O VII, and O VIII emission lines due to the enhanced solar wind flux in the vicinity of the exosphere. Using the solar wind data taken with the ACE and WIND satellites,a time correlation between the solar wind and the strong O VII line flux were investigated. We estimated necessary column densities for the solar X-ray scattering and exospheric SWCX. From these results, we argue that a part of the solar wind ions enter inside the magnetosphere and cause the SWCX reaction.Comment: 33 pages, 16 figures, accepted for publication in PAS