A Search for H-alpha Absorption in the Exosphere of the Transiting Extrasolar Planet HD 209458b

There is evidence that the transiting planet HD 209458b has a large exosphere of neutral hydrogen, based on a 15% decrement in Lyman-alpha flux that was observed by Vidal-Madjar et al. during transits. Here we report upper limits on H-alpha absorption by the exosphere. The results are based on optical spectra of the parent star obtained with the Subaru High Dispersion Spectrograph. Comparison of the spectra taken inside and outside of transit reveals no exospheric H-alpha signal greater than 0.1% within a 5.1A band (chosen to have the same Delta_lambda/lambda as the 15% Ly-alpha absorption). The corresponding limit on the column density of n=2 neutral hydrogen is N_2 <~ 10^9 cm^{-2}. This limit constrains proposed models involving a hot (~10^4 K) and hydrodynamically escaping exosphere.Comment: To appear in PASJ [9 pages, 5 figures]. Minor corrections to match published versio

Subaru HDS Transmission Spectroscopy of the Transiting Extrasolar Planet HD 209458b

We have searched for absorption in several common atomic species due to the atmosphere or exosphere of the transiting extrasolar planet HD 209458b, using high precision optical spectra obtained with the Subaru High Dispersion Spectrograph (HDS). Previously we reported an upper limit on H alpha absorption of 0.1% (3 sigma) within a 5.1\AA band. Using the same procedure, we now report upper limits on absorption due to the optical transitions of Na D, Li, H alpha, H beta, H gamma, Fe, and Ca. The 3 sigma upper limit for each transition is approximately 1% within a 0.3\AA band (the core of the line), and a few tenths of a per cent within a 2\AA band (the full line width). The wide-band results are close to the expected limit due to photon-counting (Poisson) statistics, although in the narrow-band case we have encountered unexplained systematic errors at a few times the Poisson level. These results are consistent with all previously reported detections and upper limits, but are significantly more sensitive.Comment: 10 pages, 9 figure

Magnetization Reversal and Specific Loss Power of Magnetic Nanoparticles in Cellular Environment Evaluated by AC Hysteresis Measurement

The effect of intracellular hyperthermia induced by magnetic nanoparticles (MNPs) has been evaluated using a theoretical model. In this study, magnetization reversal of MNPs in the cellular environment under an AC magnetic field was evaluated on the basis of measured AC hysteresis loops. The specific and intrinsic loss powers—SLP and ILP—were also estimated from the area of AC hysteresis loops. The measured samples were a liquid sample dispersed in water, a fixed sample mixed with an epoxy bond, and a cellular sample. In the cellular environment, the rotations of particles and magnetic moments were inhibited by particle-cell and dipole-dipole interactions, respectively. The heat dissipation of the MNPs in the cellular environment was lower than that of the liquid and fixed samples. Moreover, the SLP in a single cell was estimated. The temperature increase of a single cell was calculated on the basis of the conventional theoretical model and the SLP measured in a single cell

Measurement of the Rossiter--McLaughlin Effect in the Transiting Exoplanetary System TrES-1

We report a measurement of the Rossiter--McLaughlin effect in the transiting extrasolar planetary system TrES-1, via simultaneous spectroscopic and photometric observations with the Subaru and MAGNUM telescopes. By modeling the radial velocity anomaly that was observed during a transit, we determine the sky-projected angle between the stellar spin axis and the planetary orbital axis to be $\lambda = 30 \pm 21$ [deg]. This is the third case for which $\lambda$ has been measured in a transiting exoplanetary system, and the first demonstration that such measurements are possible for relatively faint host stars ($V \sim 12$, as compared to $V \sim 8$ for the other systems). We also derive a time of mid-transit, constraints on the eccentricity of the TrES-1b orbit ($e = 0.048 \pm 0.025$), and upper limits on the mass of the Trojan companions ($\lesssim$14 $M_{\oplus}$) at the 3$\sigma$ level.Comment: 8 pages, 5 figures, 2 tables. Published in PASJ. Corrected typo

THE CHARACTERISTICS OF HITTING MOTION USING BATS HAVING DIFFERENT LENGTH AND MASS BUT EQUAL MOMENT OF INERTIA

The aim of this study was to investigate the characteristics of hitting motion when using training bats with altered length and mass. Four different long bats (LB) and four different weight bats (WB) that had the equal moment of inertia (MOI) were manufactured based on a normal bat (NB; 0.84 m, 0.90 kg). Eleven male collegiate baseball players performed tee batting with maximal effort. The hitting motion was analyzed using a VICON (250 Hz) to collect nine reflective markers fixed on the body and bat. Results indicated that the angular displacement of the trunk twist tended to be larger in LB with increasing MOI. And it was remarkable in subjects with smaller angular displacement of trunk twist in NB. Thus, compared to WB, LB may contribute to a larger angular displacement of trunk twist, particularly in players with smaller angular displacement of trunk twist in NB

Thin film write head field analysis using a benchmark problem

A benchmark problem has been proposed by the Storage Research Consortium (SRC) in Japan, for evaluating the applicability of computer codes to 3-D nonlinear eddy current analysis of thin film magnetic recording write head. Various codes using the finite element method are compared in terms of the write head field and the computational efficiency. The difficulty in 3-D mesh generation of thin film head is also discussed. The write head fields calculated by various codes using different meshes show fairly good agreement. The calculated write head fields are verified by measurement using a stroboscopic electron beam tomography. It is found that the calculation time strongly depends on unknown variables </p