Search Publications
AKARI mission program: Excavating Mass Loss History in extended dust shells of Evolved Stars (MLHES). I. Far-IR photometry†
Yamamura, Issei; Takita, Satoshi; Izumiura, Hideyuki +3 more
We performed a far-IR imaging survey of the circumstellar dust shells of 144 evolved stars as a mission program of the AKARI infrared astronomical satellite using the Far-Infrared Surveyor (FIS) instrument. With this survey, we deliver far-IR surface brightness distributions of roughly 10' × 40' or 10' × 20' areas of the sky around the target evol…
Galactic foreground of gamma-ray bursts from AKARI Far-Infrared Surveyor
Doi, Yasuo; Onishi, Toshikazu; Zahorecz, Sarolta +8 more
We demonstrate the use of the AKARI FIS All-Sky Survey maps in the study of extragalactic objects. A quick but reliable estimate of the Galactic foreground is essential for extragalactic research in general. We explored the galactic foreground and calculated hydrogen column densities using AKARI FIS and other recent all-sky survey data, and compar…
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. …
AKARI and IRAS: From beam corrections to SEDs
Pearson, Chris; Clements, David L.; Wang, Lingyu +6 more
There is significant scientific value to be gained from combining AKARI fluxes with data at other far-infrared (IR) wavelengths from the Infrared Astronomical Satellite (IRAS) and Herschel missions. To be able to do this we must ensure that there are no systematic differences between the data sets that need to be corrected before the fluxes are co…
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…
Far-infrared dust properties of highly dust-obscured active galactic nuclei from the AKARI and WISE all-sky surveys
Malkan, Matthew; Lam, Anson; Wright, Edward
The combination of the AKARI and WISE infrared all-sky surveys provides a unique opportunity to identify and characterize the most highly dust-obscured active galactic nuclei (AGNs) in the universe. Dust-obscured AGNs are not easily detectable and are potentially underrepresented in extragalactic surveys due to their high optical extinction, but a…
Clustering of extremely red objects in the AKARI NEP-deep field
Goto, Tomotsugu; Pearson, Chris; Jeong, Woong-Seob +6 more
We study the clustering property of extremely red objects (EROs) using Canada-France-Hawaii Telescope (CFHT) surveys with 0.55 deg2 in the AKARI north ecliptic pole (NEP) deep field. EROs are selected by the color criterion of r' - Ks > 3.66, which is equivalent to (R - Ks)Vega > 5. We conducted th…
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…
SX Piscium: A near-contact mass-transferring binary with a possible brown dwarf companion
Wang, Zhi Hua; Zhu, Li Ying
SX Psc is a short-period Algol-type eclipsing binary whose photometric analysis has long been ignored. Our photometric monitoring of this target covered from 2001 December to 2018 November. Aside from some curves observed at the primary eclipses, the complete four-color light curves in the BVRcIc band were also obtained. Phot…
Observations of photospheric magnetic structure below a dark filament using the Hinode Spectro-Polarimeter
Shimojo, Masumi; Yokoyama, Takaaki; Katsukawa, Yukio
The structure of the photospheric vector magnetic field below a dark filament on the Sun is studied using the observations of the Spectro-Polarimeter attached to the Solar Optical Telescope onboard Hinode. Special attention is paid to discriminating between two suggested models, a flux rope or a bent arcade. "Inverse polarity" orientation is possi…