Search Publications
A three-dimensional velocity of an erupting prominence prior to a coronal mass ejection
Shibata, Kazunari; Ishii, Takako T.; Kitai, Reizaburo +10 more
We present a detailed three-dimensional (3D) view of a prominence eruption, coronal loop expansion, and coronal mass ejections (CMEs) associated with an M4.4 flare that occurred on 2011 March 8 in the active region NOAA 11165. Full-disk Hα images of the flare and filament ejection were successfully obtained by the Flare Monitoring Telescope (FMT) …
Studies of emission regions of the X-ray pulsar Hercules X-1 with pulse-phase-resolved spectra observed with Suzaku
Dotani, Tadayasu; Inoue, Hajime; Kondo, Keisuke
Pulse-phase-resolved X-ray spectra of the X-ray pulsar Her X-1 observed with Suzaku are analyzed. The analysis is based on a hypothesis that the observed variations of the continuum spectra associated with the neutron star spin originate in the changes of the projection areas of the emission regions viewed from the observer, and that the spectral …
Suzaku observations of Jovian diffuse hard X-ray emission
Miyoshi, Yoshizumi; Ezoe, Yuichiro; Ishikawa, Kumi +6 more
We report on results of systematic analyses of the entire three X-ray data sets of Jupiter taken by Suzaku in 2006, 2012, and 2014. Jovian diffuse hard X-ray emission was discovered by Suzaku in 2006 when the solar activity went toward its minimum. The diffuse emission was spatially consistent with the Jovian inner magnetosphere and was spectrally…
Dust dissipation timescales in the intermediate and outer regions of protoplanetary disks
Nakagawa, Takao; Kwon, Jungmi; Takita, Satoshi +2 more
Dust and gas in protoplanetary disks dissipate as central stars evolve. In order to estimate the dust dissipation timescales in the protoplanetary disks, we stacked the WISE 12 and 22, and the AKARI 90 µm survey images of known T Tauri stars and derived the average fluxes, well below the survey flux limit in the 90 µm band. We classifi…
Searching for periodic variations in radial velocities after the removal of orbital motions of spectroscopic binaries
Sato, Bun'ei; Itoh, Yoichi; Katoh, Noriyuki
This study focuses on periodic variations of radial velocities (RVs) after removing the orbital motion of 33 spectroscopic binaries. The RVs were monitored from 2003 to 2012 and published in Katoh et al. (2013, AJ, 145, 41). Their RV precision was determined to be ∼10 m s-1 utilizing an I2 cell. We investigated the periodic v…
Signatures of large-scale cold fronts in the optically-selected merging cluster HSC J085024+001536
Oguri, Masamune; Fujimoto, Ryuichi; Okabe, Nobuhiro +5 more
We represent a joint X-ray, weak-lensing, and optical analysis of the optically-selected merging cluster, HSC J085024+001536, from the Subaru HSC-SSP survey. Both the member galaxy density and the weak-lensing mass map show that the cluster is composed of south-east and north-west components. The two-dimensional weak-lensing analysis shows that th…
Spatial distribution of the X-ray-emitting plasma of SS Cygni in quiescence and outburst
Maeda, Yoshitomo; Ishida, Manabu; Hayashi, Takayuki +2 more
We present our analysis of the Suzaku data of SS Cygni (SS Cyg) from 2005 both in quiescence and outburst. A fluorescent iron Kα line bears significant information about the geometry of an X-ray-emitting hot plasma and a cold reflector, such as the surfaces of the white dwarf (WD) and the accretion disk (AD). Our reflection simulation has revealed…
The First VERA Astrometry Catalog
Nakanishi, Hiroyuki; Hirota, Tomoya; Kurayama, Tomoharu +59 more
We present the first astrometry catalog from the Japanese VLBI (very long baseline interferometer) project VERA (VLBI Exploration of Radio Astrometry). We have compiled all the astrometry results from VERA, providing accurate trigonometric-annual-parallax and proper-motion measurements. In total, 99 maser sources are listed in the VERA catalog. Am…
Elemental abundances of M dwarfs based on high-resolution near-infrared spectra: Verification by binary systems
Kuzuhara, Masayuki; Omiya, Masashi; Reiners, Ansgar +4 more
M dwarfs are prominent targets of planet search projects, and their chemical composition is crucial to understanding the formation process or interior of orbiting exoplanets. However, measurements of elemental abundances of M dwarfs have been limited due to difficulties in the analysis of their optical spectra. We conducted a detailed chemical ana…
Gaia's detectability of black hole-main sequence star binaries formed in open clusters
Fujii, Michiko S.; Kumamoto, Jun; Shikauchi, Minori +1 more
Black hole-main sequence star (BH-MS) binaries are one of the targets of future data releases of the astrometric satellite Gaia. They are supposed to be formed in two main sites: a galactic field and star clusters. However, previous work has never predicted the number of BH-MS binaries originating in the latter sites. In this paper we estimate the…