Aoyama Gakuin University

About: Aoyama Gakuin University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Superconductivity & Thin film. The organization has 3494 authors who have published 6419 publications receiving 115648 citations. The organization is also known as: Aoyama gakuin daigaku.

A Detailed Study of Non-thermal X-Ray Properties and Interstellar Gas toward the γ-Ray Supernova Remnant RX J1713.7-3946

Abstract: We have carried out a spectral analysis of the Suzaku X-ray data in the 0.4-12 keV range toward the shell-type very high-energy γ-ray supernova remnant (SNR) RX J1713.7–3946. The aims of this analysis are to estimate detailed X-rays spectral properties at a high angular resolution up to 2 arcmin and to compare them with the interstellar gas. The X-ray spectrum is non-thermal and used to calculate absorbing column density, photon index, and absorption-corrected X-ray flux. The photon index varies significantly from 2.1 to 2.9. It is shown that the X-ray intensity is well correlated with the photon index, especially in the west region, with a correlation coefficient of 0.81. The X-ray intensity tends to increase with the averaged interstellar gas density while the dispersion is relatively large. The hardest spectra, with photon indexes of less than 2.4, are found outside of the central 10 arcmin of the SNR, from the north to the southeast (~430 arcmin2) and from the southwest to the northwest (~150 arcmin2). The former region shows low interstellar gas density, while the latter shows high interstellar gas density. We present a discussion of possible scenarios that explain the distribution of the photon index and its relationship with the interstellar gas.

Ferromagnetic spin ordering on carbon nanotubes with topological line defects

Abstract: We report first-principles total-energy electronic-structure calculations in the density functional theory performed for carbon nanotubes with a topological line defect consisting of pentagon and octagon rings. We find that the ground state of the nanotubes with the topological line defect is ferromagnetic with small but finite magnetic moment of about $0.04{\ensuremath{\mu}}_{B}∕\mathrm{\AA{}}$. Detailed analyses of energy bands and spin densities unequivocally reveal the nature of the ferromagnetic spin ordering which is associated with the peculiar edge-localized states of graphite flakes.