We explore physics behind hot, energetic phenomena in the universe through a wide variety of telescopes including space-based X-ray observatories. Our research particularly focuses on high energy physical processes associated with supernova remnants, neutron stars, and black holes. We also develop new observational instruments for future satellite missions.




馬場准教授が主著の論文”Spectral Break of Energetic Pulsar Wind Nebulae Detected with Wideband X-ray Observations”がPASJに受理されました。パルサー星雲からのX線放射には折れ曲がりが普遍的に存在することを初めて示し、その起源について議論しています。

Asymmetric Expansion of the Fe ejecta in Kepler’s Supernova Remnant

Our paper titled “Asymmetric Expansion of the Fe ejecta in Kepler’s Supernova Remnant” has been accepted for publication in PASJ. arXiv: https://arxiv.org/abs/1807.04029 The ejecta kinematics of supernova remnants (SNRs) is one of crucial clues to understand the explosion mechanism of type Ia supernovae (SNe). In particular, the kinematic asymmetry of iron-peak elements provides the key to understanding physical processes taking place in the core of the exploding white dwarfs (WDs) although it has been poorly understood by observations. Kasuga et al. shows for the first time the asymmetric expansion structure in the line-of-sight direction of Fe ejecta in Kepler’s SNR …

Radioactivation background in satellites’ orbits

Our paper titled “Modeling of proton-induced radioactivation background in hard X-ray telescopes: Geant4-based simulation and its demonstration by Hitomi’s measurement in a low Earth orbit” has been published in Nuclear Instruments and Methods A. arXiv: https://arxiv.org/abs/1804.00827 ADS: http://adsabs.harvard.edu/abs/2018NIMPA.891…92O Hard X-ray observation must be conducted in a satellite’s orbit due to atmospheric absorption, and therefore suffers from significant backgrounds induced by cosmic rays and/or geomagnetically trapped charged particles. Hirokazu Odaka et al. have developed a new, effective, general-purpose framework of full Monte Carlo simulation of radioactivation background. We applied this framework to data measured with the Hard X-ray Imager onboard the …