Search Publications
A study of the long term evolution in active region upflows
Harra, Louise K.; Ugarte-Urra, Ignacio; Baker, Deborah +5 more
Since their discovery, upflows at the edges of active regions have attracted a lot of interest, primarily as they could potentially contribute to the slow solar wind. One aspect that has not been studied yet is how the long term evolution of active regions impacts the upflows. In this work, we analyze one active region that survives three solar ro…
Suzaku Wide-band All-sky Monitor (WAM) observations of GRBs and SGRs
Yamaoka, Kazutaka; Fukazawa, Yasushi; Hanabata, Yoshitaka +29 more
We will review results for gamma-ray bursts (GRBs) and soft gamma repeaters (SGRs), obtained from the Suzaku Wide-band All-sky Monitor (WAM) which operated for about 10 years from 2005 to 2015. The WAM is a BGO (bismuth germanate: Bi4Ge3O12) lateral shield for the Hard X-ray Detector (HXD), used mainly for rejectin…
ASASSN-16eg: New candidate for a long-period WZ Sge-type dwarf nova
Nogami, Daisaku; Kato, Taichi; Isogai, Keisuke +19 more
We report on our photometric observations of the 2016 superoutburst of ASASSN-16eg. This object showed a WZ Sge-type superoutburst with prominent early superhumps with a period of 0.075478(8) d and a post-superoutburst rebrightening. During the superoutburst plateau, it showed ordinary superhumps with a period of 0.077880(3) d and a period derivat…
Study of the progenitor of the magnetar 1E 2259+586 through Suzaku observations of the associated supernova remnant CTB 109
Enoto, Teruaki; Makishima, Kazuo; Nakano, Toshio +4 more
We present a study of the progenitor of the magnetar 1E 2259+586, from Suzaku observations of the associated supernova remnant CTB 109. The Suzaku spectra, either spatially integrated or spatially resolved, were successfully described by a two-component plasma model, which reconfirms a previous Chandra result on the northwestern part of this remna…
Observational study on the fine structure and dynamics of a solar jet. I. Energy build-up process around a satellite spot
Shibata, Kazunari; Ichimoto, Kiyoshi; Ueno, Satoru +3 more
We report on a solar jet phenomenon associated with successive flares on 2014 November 10. These explosive events were involved with the satellite spots' emergence around a δ-type sunspot in the decaying active region NOAA 12205. The data for this jet were provided by the Solar Dynamics Observatory, the X-Ray Telescope aboard Hinode, and the Inter…
Suzaku observations of spectral variations of the ultra-luminous X-ray source Holmberg IX X-1
Makishima, Kazuo; Nakazawa, Kazuhiro; Kobayashi, Shogo B.
Observations of the ultra-luminous X-ray source (ULX) Holmberg IX X-1 were carried out with Suzaku twice, once on 2012 April 13 and then on 2012 October 24, with exposures of 180 ks and 217 ks, respectively. The source showed a hard power-law shaped spectrum with a mild cutoff at ∼8 keV, which is typical of ULXs when they are relatively dim. On bo…
Surface brightness correction for compact extended sources observed by the AKARI Far-Infrared Surveyor in the slow-scan mode
Shirahata, Mai; Yamamura, Issei; Takita, Satoshi +5 more
We present a general surface brightness correction method for compact extended sources imaged in the slow-scan pointed observation mode of the Far-Infrared Surveyor (FIS) aboard the AKARI infrared astronomical satellite. Our method recovers correct surface brightness distribution maps by rescaling archived raw FIS maps using the surface-brightness…
Suzaku and Chandra observations of the galaxy cluster RXC J1053.7+5453 with a radio relic
Fukazawa, Yasushi; Nakazawa, Kazuhiro; Ohashi, Takaya +10 more
We present the results of Suzaku and Chandra observations of the galaxy cluster RXC J1053.7+5453 (z = 0.0704), which contains a radio relic. The radio relic is located at a distance of ∼540 kpc from the X-ray peak toward the west. We measured the temperature of this cluster for the first time. The resultant temperature in the center is ∼1.3 keV, w…
Temporal relations between magnetic bright points and the solar sunspot cycle
Van Doorsselaere, Tom; Utz, Dominik; Muller, Richard
The Sun shows a global magnetic field cycle traditionally best visible in the photosphere as a changing sunspot cycle featuring roughly an 11-year period. In addition we know that our host star also harbours small-scale magnetic fields often seen as strong concentrations of magnetic flux reaching kG field strengths. These features are situated in …
A broad spectral feature detected during the cooling phase of a type I X-ray burst from GRS 1747-312 with Suzaku
Dotani, Tadayasu; Maeda, Yoshitomo; Mori, Hideyuki +3 more
We analyzed the Suzaku archive data of a type I X-ray burst from GRS 1747-312, a low-mass X-ray binary located in the globular cluster Terzan 6. During the Galactic bulge mapping observations with Suzaku, which covered Terzan 6, an X-ray burst of long duration and with moderate photospheric-radius expansion was serendipitously detected and was con…