Search Publications
Initial Helioseismic Observations by Hinode/SOT
Tsuneta, Saku; Shimizu, Toshifumi; Zhao, Junwei +12 more
Results from initial helioseismic observations by the Solar Optical Telescope on-board Hinode are reported. It has been demonstrated that intensity oscillation data from the Broadband Filter Imager can be used for various helioseismic analyses. The k - ω power spectra, as well as the corresponding time-distance cross-correlation function, which pr…
Suzaku Observations of HESS J1616-508: Evidence for a Dark Particle Accelerator
Mori, Hideyuki; Porter, Frederick S.; Kokubun, Motohide +15 more
We observed the bright unidentified TeV γ-ray source HESS J1616-508 with the X-ray Imaging Spectrometers onboard the Suzaku satellite. No X-ray counterpart was found to a limiting flux of 3.1 × 10-13 erg s-1 cm-2 in the 2-10keV band, which is some 60-times below the γ-ray flux in the 1-10TeV band. This object is br…
Properties of UIR Bands in NGC6946 Based on Mid-Infrared Imaging and Spectroscopy with Infrared Camera on Board AKARI
Serjeant, S.; Ohyama, Y.; Takagi, T. +23 more
We present results on mid-infrared imaging and spectroscopic observations of the nearby late-type spiral NGC6946 with the Infrared Camera on board AKARI. Based on mid-infrared imaging with the S7 (7µm may be tools to measure the star-formation activity in remote galaxies if these ratios and their variations are well examined and established …
Detection of Highly-Ionized Carbon and Nitrogen Emission Lines from the Cygnus Loop Supernova Remnant with the Suzaku Observatory
Katsuda, Satoru; Kokubun, Motohide; Hughes, John P. +3 more
We present the results of a Suzaku observation at the northeastern limb of the Cygnus Loop supernova remnant. The high detection efficiency together with the high spectral resolution of the Suzaku X-ray CCD cameras enables us to detect highly-ionized C and N emission lines from the Cygnus Loop for the first time. We performed an annular spectral a…
Umbral Fine Structures in Sunspots Observed with Hinode Solar Optical Telescope
Matsumoto, Takuma; Shibata, Kazunari; Tsuneta, Saku +15 more
A high resolution imaging observation of a sunspot umbra was made with the Hinode Solar Optical Telescope. Filtergrams at wavelengths of the blue and green continua were taken during three consecutive days. The umbra consisted of a dark core region, several diffuse components, and numerous umbral dots. We derived basic properties of umbral dots (U…
Suzaku Observation of Diffuse X-Ray Emission from the Carina Nebula
Hamaguchi, Kenji; Petre, Robert; Tsujimoto, Masahiro +9 more
We studied extended X-ray emission from the Carina Nebula taken with the Suzaku CCD camera XIS on 2005 August 29.The X-ray morphology, plasma temperature, and absorption to the plasma are consistent with the earlier Einstein results.The Suzaku spectra newly revealed emission lines from various species, including oxygen, but not from nitrogen.This …
Hinode SP Vector Magnetogram of AR10930 and Its Cross-Comparison with MDI
Moon, Yong-Jae; Shimojo, Masumi; Tsuneta, Saku +17 more
We present one Hinode Spectropolarimeter (SP) magnetogram of AR 10930 that produced several major flares. The inversion from Stokes profiles to magnetic field vectors was made using the standard Milne-Eddington code. We successfully applied the Uniform Shear Method for resolving the 180° ambiguity to the magnetogram. The inversion gave very strong…
An Apparent Hard X-Ray Decline of CH Cygni
Ishida, Manabu; Mori, Hideyuki; Terada, Yukikatsu +4 more
CH Cygni is a symbiotic star consisting of an M giant and an accreting white dwarf, which is known to be a highly variable X-ray source with a complex, two-component, spectra. Here, we report on two Suzaku observations of CH Cyg, taken in 2006 January and May, during which the system was seen to be in a soft X-ray bright, hard X-ray faint state. B…
In-Orbit Focal Adjustment of the AKARI Telescope with Infrared Camera (IRC) Images
Takagi, T.; Wada, T.; Onaka, T. +4 more
AKARI, currently in space, carries onboard a cryogenically cooled light-weight telescope with silicon carbide mirrors. The wavefront error of the AKARI telescope, obtained in laboratory measurements at 9 K, showed that the expected in-orbit imaging performance was diffraction-limited at a wavelength of 6.2 µm, slightly degraded from that exp…
Discovery of a Possible X-Ray Counterpart to HESS J1804-216
Maeda, Yoshitomo; Kokubun, Motohide; Takahashi, Tadayuki +10 more
Suzaku deep observations have discovered two highly significant nonthermal X-ray sources, Suzaku J1804-2142 (Src 1) and Suzaku J1804-2140 (Src 2), positionally coincident with the unidentified TeV γ-ray source, HESS J1804-216. The X-ray sources are not time variable and show no counterpart in other wavebands, except for the TeV source. Src 1 is un…