Search Publications
Suzaku Wide-Band Observations of SN1006
Petre, Rob; Fukazawa, Yasushi; Kokubun, Motohide +17 more
We report on the wide-band spectra of SN1006, as observed by Suzaku. Thermal and nonthermal emissions were successfully resolved thanks to the excellent spectral response of Suzaku's X-ray CCD XIS. The nonthermal emission could not be reproduced by a simple power-law model, but needed a roll-off at 5.7 × 1016Hz = 0.23keV. The roll-off f…
Cooperative Observation of Ellerman Bombs between the Solar Optical Telescope aboard Hinode and Hida/Domeless Solar Telescope
Matsumoto, Takuma; Shibata, Kazunari; Tsuneta, Saku +13 more
High-resolution CaIIH broad-band filter images of NOAA10933 on 2007 January 5 were obtained by the Solar Optical Telescope aboard the Hinode satellite. Many small-scale (∼1") bright points were observed outside the sunspot and inside the emerging flux region. We identified some of these bright points with Ellerman bombs (EBs) by using Hα images ta…
Low/Hard State Spectra of GRO J1655-40 Observed with Suzaku
Dotani, Tadayasu; Yaqoob, Tahir; Yamaoka, Kazutaka +23 more
The Galactic black-hole binary GROJ1655-40, a source harboring superluminal jets, was observed with Suzaku on 2005 September 22-23. The source was detected over a broad and continuous energy range of 0.7-300keV, with an intensity of ∼50mCrab at 20keV. At a distance of 3.2kpc, the 0.7-300keV luminosity was ∼5.2 × 1036 ergs-1 (…
Suzaku Wide-Band X-Ray Spectroscopy of the Seyfert2 AGN in NGC 4945
Done, Chris; Isobe, Naoki; Gandhi, Poshak +13 more
Suzaku observed a nearby Seyfert2 galaxy, NGC 4945, which hosts one of the brightest active galactic nuclei above 20keV. Combining data from the two detectors aboard Suzaku, the AGN intrinsic nuclear emission and its reprocessed signals were observed simultaneously. The intrinsic emission is highly obscured with an absorbing column of ∼5×1024…
A Time-Variable X-Ray Echo: Indications of a Past Flare of the Galactic-Center Black Hole
Koyama, Katsuji; Matsumoto, Hironori; Tsuru, Takeshi Go +1 more
A time-variability study of the neutral iron line flux at 6.40keV in the Sgr B2 region from data of Suzaku and Chandra is presented. The highly ionized iron line at 6.68keV is due to Galactic Center Diffuse X-rays, and is thus time invariable. By comparing the 6.68keV and 6.40keV line fluxes, we found that the 6.40keV flux from the Sgr B2 complex …
Spectral Study of the Galactic Ridge X-Ray Emission with Suzaku
Tsujimoto, Masahiro; Kokubun, Motohide; Koyama, Katsuji +7 more
In order to carry out a precise spectral study of the Galactic Ridge X-ray Emission using Suzaku, we have observed a typical Galactic plane field at (l,b) = (28°46, -0°20), which is already deeply observed with Chandra, and known to be devoid of bright X-ray point sources. Thanks to the low background and high spectral resolution of Suzaku, we wer…
Measuring the Broad-Band X-Ray Spectrum from 400eV to 40keV in the Southwest Part of the Supernova Remnant RXJ1713.7-3946
Petre, Robert; Kokubun, Motohide; Nakazawa, Kazuhiro +13 more
We report on results from Suzaku broadband X-ray observations of the southwest part of the galactic supernova remnant (SNR) RXJ1713.7-3946 with an energy coverage of 0.4-40keV. The X-ray spectrum, presumably of synchrotron origin, is known to be completely lineless, making this SNR ideally suited for a detailed study of the X-ray spectral shape fo…
Suzaku Spectroscopy of an X-Ray Reflection Nebula and a New Supernova Remnant Candidate in the SgrB1 Region
Koyama, Katsuji; Nakajima, Hiroshi; Matsumoto, Hironori +7 more
We made a 100 ks observation of the Sagittarius (Sgr) B1 region at (l, b) = (0°.5, -0°.1) near to the Galactic center (GC) with the Suzaku/XIS. Emission lines of SXV, FeI, FeXXV, and FeXXVI were clearly detected in the spectrum. We found that the FeXXV and FeXXVI line emissions smoothly distribute over the SgrB1 and B2 regions connecting from the …
In-Orbit Timing Calibration of the Hard X-Ray Detector on Board Suzaku
Dotani, Tadayasu; Enoto, Teruaki; Yamaoka, Kazutaka +28 more
The hard X-ray detector (HXD) aboard the X-ray satellite Suzaku is designed to have a good timing capability with a 61µs time resolution. In addition to detailed descriptions of the HXD timing system, results of in-orbit timing calibration and the performance of the HXD are summarized. The relative accuracy of time measurements of the HXD ev…
Suzaku Observations of the North Polar Spur: Evidence for Nitrogen Enhancement
Miller, Eric D.; Katsuda, Satoru; Kokubun, Motohide +10 more
We present observations of the North Polar Spur (NPS) using the X-ray Imaging Spectrometer (XIS) aboard the Suzaku X-ray satellite. The NPS is a large region of enhanced soft X-ray and radio emission projected above the plane of the Galaxy, likely produced by a series of supernovae and stellar winds from the nearby Sco-Cen OB association. The exce…