Search Publications
A NuSTAR study of the 55 ks hard X-ray pulse-phase modulation in the magnetar 4U 0142+61
Enoto, Teruaki; Makishima, Kazuo; Nakazawa, Kazuhiro +1 more
Archival NuSTAR data of the magnetar 4U 0142+61, acquired in 2014 March for a total time span of 258 ks, were analyzed. This is to reconfirm the 55 ks modulation in the hard X-ray pulse phases of this source, found with a Suzaku observation in 2009 (Makishima et al., 2014, Phys. Rev. Lett., 112, 171102). Indeed, the 10-70 keV X-ray pulsation, dete…
Suzaku detection of enigmatic geocoronal solar wind charge exchange event associated with coronal mass ejection
Miyoshi, Yoshizumi; Ezoe, Yuichiro; Ishikawa, Kumi +5 more
Suzaku detected an enhancement of the soft X-ray background associated with solar eruptions on 2013 April 14-15. The solar eruptions were accompanied by an M6.5 solar flare and a coronal mass ejection with magnetic flux ropes. The enhanced soft X-ray background showed a slight variation over half a day and then a clear one in a few hours. The form…
X-ray spectra of Sagittarius A East and diffuse X-ray background near the Galactic center
Koyama, Katsuji; Nobukawa, Masayoshi; Uchiyama, Hideki +3 more
This paper reports the analysis procedure and results of simultaneous spectral fits of the Suzaku archive data for Sagittarius (Sgr) A East and the nearby Galactic center X-ray emission (GCXE). The results are that the mixed-morphology supernova remnant Sgr A East has a recombining plasma (RP) with Cr and Mn Heα lines, and a power-law component (P…
Ionization age of iron ejecta in the Galactic Type Ia supernova remnant G306.3-0.9
Uchida, Hiroyuki; Bamba, Aya; Tsuru, Takeshi Go +5 more
We present a 190 ks observation of the Galactic supernova remnant (SNR) G306.3-0.9 with Suzaku. To study ejecta properties of this possible Type Ia SNR, the absolute energy-scale at the Fe-K band was calibrated to a level of uncertainty less than 10 eV by a cross-calibration with the Hitomi microcalorimeter using the Perseus cluster spectra. This …
X-ray and optical observations of the black hole candidate MAXI J1828-249
Makishima, Kazuo; Ueda, Yoshihiro; Itoh, Ryosuke +8 more
We report results from X-ray and optical observations of the Galactic black hole candidate MAXI J1828-249 performed with Suzaku and the Kanata telescope around the X-ray flux peak in the 2013 outburst. The time-averaged X-ray spectrum covering 0.6-168 keV was approximately characterized by a strong multi-color disk blackbody component with an inne…
Spectral properties of gamma-ray bursts observed by the Suzaku wide-band all-sky monitor
Yamaoka, Kazutaka; Fukazawa, Yasushi; Kokubun, Motohide +17 more
We have systematically studied the spectral properties of 302 localized gamma-ray bursts (GRBs) observed by the Suzaku wide-band all-sky monitor (WAM) from 2005 August to 2010 December. The energy spectra in the 100-5000 keV range integrated over the entire emission and the 1 s peak were fitted by three models: a single power law, a power law with…
An enigmatic hump around 30 keV in Suzaku spectra of Aquila X-1 in the hard state
Makishima, Kazuo; Tamagawa, Toru; Nakano, Toshio +4 more
The typical accreting neutron star, Aquila X-1, was observed with Suzaku seven times in the decay phase of an outburst in 2007 September-October. Among them, the second to the fourth observations were performed 10 to 22 days after the outburst peak, when the source was in the hard state with a luminosity of 2 × 1036 erg s-1. …
Suzaku observation of Jupiter's X-rays around solar maximum
Miyoshi, Yoshizumi; Ezoe, Yuichiro; Ishikawa, Kumi +6 more
We report on results of imaging and spectral studies of X-ray emission from Jupiter observed by Suzaku. In 2006, Suzaku found diffuse X-ray emission in 1-5 keV associated with Jovian inner radiation belts. It has been suggested that the emission is caused by the inverse-Compton scattering by ultra-relativistic electrons (∼50 MeV) in Jupiter's magn…
Suzaku observation of diffuse X-ray emission from a southwest region of the Carina Nebula
Hamaguchi, Kenji; Ezoe, Yuichiro; Ohashi, Takaya +2 more
A southwest region of the Carina Nebula was observed with the Suzaku observatory for 47ks in 2010 December. This region shows distinctively soft X-ray emission in the Chandra campaign observations. Suzaku clearly detects the diffuse emission above known foreground and background components between 0.4-5keV at the surface brightness of 3.3× 10^{-14…