SPIN-WAVE EXCITATIONS IN Gd AT LOW TEMPERATURES

It has been manifestly demonstrated that Gd is one of the best example to be realistically applied to the spin-wave theory of Heisenberg model for the localized magnetic moment. The magnetization of Gd has been measured in the temperature 4<T<310 K at a constant magnetic field of 6 kOe using a homemade vibrating sample magnetometer. We present an exact analysis of the spin-wave excitations for Gd. In the presence of an applied magnetic field, H, an energy gap exists in the spin-wave dispersion relation. As a consequence, the temperature dependence of the magnetization for ferromagnets must differ from the simple Bloch T³/² law. The low temperature magnetization per gram is found to obey the form: Δσ(T)/σ(0) = BZ(3/2,Tℊ/T)T³/² + CZ(5/2, Tℊ/T)T⁵/², where B and C are constants and Δσ(T) = σ(0) - σ(T). The modification factors Z(3/2, Tℊ/T) and Z(5/2, Tℊ/T) are the characteristic functions of T and the magnetic field, H. The spontaneous magnetization of ferromagnetic Gd follows BZ(3/2,Tℊ/T) T³/² relation (the modified Bloch T³/² law) with remarkable fidelity below 200 K

Coupled spin-charge-phonon fluctuation in the all-in/all-out antiferromagnet Cd2Os2O7

We report on a spin-charge fluctuation in the all-in/all-out pyrochlore magnet Cd2Os2O7, where the spin fluctuation is driven by the conduction of thermally excited electrons/holes and associated fluctuation of Os valence. The fluctuation exhibits an activation energy significantly greater than the spin-charge excitation gap and a peculiar frequency range of 10(6)-10(10) s(-1). These features are attributed to the hopping motion of carriers as small polarons in the insulating phase, where the polaron state is presumably induced by the magnetoelastic coupling via the strong spin-orbit interaction. Such a coupled spin-charge-phonon fluctuation manifests as a part of the metal-insulator transition that is extended over a wide temperature range due to the modest electron correlation comparable with other interactions characteristic for 5d-subshell systems

ERO R1 in CL0939+4713 field - Evidence for an S0-like galaxy at z \sim 1.5

We present further observations of the extremely red object ERO J094258+4659.2, identified by \citet{iye00} as ERO R1 in their deep images of the cluster A851. We estimate its redshift independently by eight-band photometric redshift determination and cross-correlation of a new H-band spectrum with the optical spectra of local E/S0 galaxies, and conclude that it lies at $z \sim 1.5$. Although its colors are consistent both with an elliptical galaxy and an S0 galaxy at that redshift, its elongated shape and exponential luminosity profile suggest the presence of an evolved stellar disk component. We rule out the possibility that these properties are strongly influenced by gravitational lensing by the foreground cluster, and therefore conclude that this object is more likely to be an S0-like galaxy, rather than a lensed elliptical. The H-band spectrum does not show strong H$\alpha$ emission and the star formation rate therefore appears to be very modest. The presence of such a galaxy with an apparently relaxed disk of stars at this high redshift provides a new and strong constraint on theoretical models which aim to explain the formation and evolution of galaxies.Comment: 23 pages, 9 figures, Submitted to the Astrophysical Journa

The Universal Initial Mass Function In The XUV Disk of M83

We report deep Subaru Halpha observations of the XUV disk of M83. These new observations enable the first complete census of very young stellar clusters over the entire XUV disk. Combining Subaru and GALEX data with a stellar population synthesis model, we find that (1) the standard, but stochastically-sampled, initial mass function (IMF) is preferred over the truncated IMF, because there are low mass stellar clusters (10^{2-3}Msun) that host massive O-type stars; that (2) the standard Salpeter IMF and a simple aging effect explain the counts of FUV-bright and Halpha-bright clusters with masses >10^3Msun; and that (3) the Halpha to FUV flux ratio over the XUV disk supports the standard IMF. The Subaru Prime Focus Camera (Suprime-Cam) covers a large area even outside the XUV disk -- far beyond the detection limit of the HI gas. This enables us to statistically separate the stellar clusters in the disk from background contamination. The new data, model, and previous spectroscopic studies provide overall consistent results with respect to the internal dust extinction (Av~0.1 mag) and low metallicity (~0.2Zsun) using the dust extinction curve of SMC.Comment: 11 pages, 8 figures. Accepted for publication in Ap

Detection and management of cardiomyopathy in female dystrophinopathy carriers

Regular health checkups for mothers of patients with Duchenne muscular dystrophy have been performed at National Hospital Organization Tokushima Hospital since 1994. Among 43 mothers participated in this study, 28 dystrophinopathy carriers were identified. Skeletal and cardiac muscle functions of these subjects were examined. High serum creatine kinase was found in 23 subjects (82.1%). Obvious muscle weakness was present in 5 (17.8%) and had progressed from 1994 to 2015. Cardiomyopathy was observed in 15 subjects (60.0%), including dilated cardiomyopathy-like damage that was more common in the left ventricular (LV) posterior wall. Late gadolinium enhancement on cardiac MRI was found in 5 of 6 subjects, suggesting fibrotic cardiac muscle. In speckle tracking echocardiography performed seven years later, global longitudinal strain was decreased in these subjects, indicating LV myocardial contractile abnormality. These results suggest that female dystrophinopathy carriers should receive regular checkups for detection and treatment of cardiomyopathy, even if they have no cardiac symptoms