Hajime Takami

Implications of Ultra-High-Energy Cosmic Rays for Transient Sources in the Auger Era (2008)

Murase, Kohta, Takami, Hajime

We study about ultra-high-energy cosmic rays (UHECRs) from transient sources, propagating in the Galactic and intergalactic space. Based on the recent observational results, we also estimate upper...

Implications to Sources of Ultra-high-energy Cosmic Rays from their Arrival Distribution (2008)

Takami, Hajime, Sato, Katsuhiko

We estimate the local number density of sources of ultra-high-energy cosmic rays (UHECRs) based on the statistical features of their arrival direction distribution. We calculate the arrival...

Nonthermal neutrinos from supernovae leaving a magnetar (2008)

Horiuchi, Shunsaku, Suwa, Yudai, Takami, Hajime, Ando, Shin'ichiro, Sato, Katsuhiko

Under the fossil field hypothesis of the origin of magnetar magnetic fields, the magnetar inherits its magnetic field from its progenitor. We show that during the supernova of such a progenitor,...

Distortion of Ultra-high-energy sky by Galactic Magnetic Field (2007)

Takami, Hajime, Sato, Katsuhiko

We investigate the deflections of UHE protons by Galactic magnetic field(GMF) using four conventional GMF models in order to discuss the positional correlation between the arrival distribution of...

Estimation Prospects of the Source Number Density of Ultra-high-energy Cosmic Rays (2007)

Takami, Hajime, Sato, Katsuhiko

We discuss the possibility of accurately estimating the source number density of ultra-high-energy cosmic rays (UHECRs) using small-scale anisotropy in their arrival distribution. The arrival...

Towards unravelling the structural distribution of ultra-high-energy cosmic ray sources (2007)

Takami, Hajime, Sato, Katsuhiko

We investigate the possibility that near future observations of ultra-high-energy cosmic rays (UHECRs) can unveil their local source distribution, which reflects the observed local structures if...

Propagation of Ultra-high-energy Protons in Cosmic Magnetic Fields (2007)

Takami, Hajime, Sato, Katsuhiko

We simulate the arrival distribution of ultra-high-energy (UHE) protons by following their propagation processes in several strengths of a structured extragalactic magnetic field (EGMF). Comparing...

Cosmogenic neutrinos as a probe of the transition from Galactic to extragalactic cosmic rays (2007)

Takami, Hajime, Murase, Kohta, Nagataki, Shigehiro, Sato, Katsuhiko

Whether the ankle is the transition point of Galactic/extragalactic cosmic rays or the pair-creation dip is an widely-discussed problem for astroparticle physics. In this work, we discuss the...

Propagation of Ultra-High Energy Cosmic Rays above $10^{19}$ eV in a Structured Extragalactic Magnetic Field and Galactic Magnetic Field (2005)

Takami, Hajime, Yoshiguchi, Hiroyuki, Sato, Katsuhiko

We present numerical simulations on propagation of Ultra-High Energy Cosmic Rays (UHECRs) above $10^{19}$ eV in a structured extragalactic magnetic field (EGMF) and simulate their arrival...