Search Publications
O I fluorescent line contamination in soft X-ray diffuse background obtained with Suzaku/XIS
Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Takei, Yoh +1 more
The quantitative measurement of O VII line intensity is a powerful method for understanding the soft X-ray diffuse background. By systematically analyzing the O VII line intensity in 145 high-latitude Suzaku/XIS observations, the flux of O I fluorescent line in the XIS spectrum, contaminating the O VII l…
Coronal behavior before the large flare onset
Kusano, Kanya; Bamba, Yumi; Imada, Shinsuke
Flares are a major explosive event in our solar system. They are often followed by a coronal mass ejection that has the potential to trigger geomagnetic storms. There are various studies aiming to predict when and where the flares are likely to occur. Most of these studies mainly discuss the photospheric and chromospheric activity before the flare…
Temperature and entropy profiles to the virial radius of the Abell 1246 cluster observed with Suzaku
Sato, Kosuke; Ohashi, Takaya; Yamasaki, Noriko Y. +2 more
We report properties of the intracluster medium (ICM) in Abell 1246 to the virial radius (r200) and further outside as observed with Suzaku. The ICM emission is clearly detected to r200, and we derive profiles of electron temperature, density, entropy, and cluster mass based on the spectral analysis. The temperature shows var…
Suzaku view of the neutron star in the dipping source 4U 1822-37
Enoto, Teruaki; Makishima, Kazuo; Zhang, Zhongli +2 more
The dipping X-ray source 4U 1822-37 was observed by Suzaku on 2006 October 20 for a net exposure of 37 ks. The source was detected with the XIS at a 1-10 keV flux of 5.5 × 10-10 erg cm-2 s-1, and with the HXD (HXD-PIN) at a 10-50 keV flux of 8.9 × 10-10 erg cm-2 s-1. With HXD-PIN, t…
Structual study of Galactic hot gas toward Markarian 421 from X-ray absorption and emission lines
Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Wang, Q. Daniel +4 more
We present a structural study of the hot ISM in the Galactic halo along the sight line toward the bright active galactic nucleus Mkn 421. The O VII and O VIII absorption lines were measured with the Low Energy Transmission Grating Spectrograph aboard Chandra toward Mkn 421; the O VII and O VIII emission lines were observed in the adjacent fields o…
Coronal loops above an active region: Observation versus model
Peter, Hardi; Bingert, Sven; Bourdin, Philippe-A.
We conducted a high-resolution numerical simulation of the solar corona above a stable active region. The aim is to test the field line braiding mechanism for a sufficient coronal energy input. We also check the applicability of scaling laws for coronal loop properties like the temperature and density. Our 3D MHD model is driven from below by Hino…
X-ray spectroscopy of the mixed morphology supernova remnant W 28 with XMM-Newton
Ishida, Manabu; Bamba, Aya; Tatematsu, Ken'ichi +6 more
We report on spatially resolved X-ray spectroscopy of the north-eastern part of the mixed morphology supernova remnant (SNR) W 28 with XMM-Newton. The observed field of view includes a prominent and twisted shell emission forming the edge of this SNR as well as part of the center-filled X-ray emission brightening toward the south-west edge of the …
Comparison between Hinode/SOT and SDO/HMI, AIA data for the study of the solar flare trigger process
Kusano, Kanya; Bamba, Yumi; Iida, Yusuke +1 more
Understanding the mechanism that produces solar flares is important not only from the scientific point of view but also for improving space weather predictability. There are numerous observational and computational studies that have attempted to reveal the onset mechanism of solar flares. However, the underlying mechanism of flare onset remains el…
Probing the accretion scheme of the dipping X-ray binary 4U 1915-05 with Suzaku
Makishima, Kazuo; Zhang, Zhongli; Sasano, Makoto +2 more
The dipping low-mass X-ray binary 4U 1915-05 was observed by Suzaku on 2007 November 8 for a net exposure of 39 ks. It was detected by the XIS with a 0.8-10 keV signal rate of 9.84 ± 0.01 cts s-1 per camera, and HXD-PIN with a 12-45 keV signal rate of 0.29 ± 0.01 cts s-1. After removing the periodic dips and an X-ray burst, t…
VLBI observations of H2O maser annual parallax and proper motion in IRAS 20143+3634: Reflection on the Galactic constants
Hayashi, Masahiko; Nakagawa, Akiharu; Omodaka, Toshihiro +8 more
We report the results of very long baseline interferometry (VLBI) observations of H2O masers in the IRAS 20143+3634 star-forming region (SFR) using VERA (VLBI Exploration of Radio Astrometry). By tracking masers for a period of over two years we measured a trigonometric parallax of π = 0.367 ± 0.037 mas, corresponding to a source distan…