Search Publications
Statistical Studies on the Excess Peak Flux in Soft X-rays and EUV Bands from Solar Flares
Cai, L.; Zhang, D. H.; Hao, Y. Q. +2 more
Based on the solar X-ray data in the band of 0.1 - 0.8 nm observed by Geostationary Operational Environmental Satellites (GOES), the XUV and EUV data in the bands of 26 - 34 nm and 0.1 - 50 nm observed by the Solar EUV Monitor (SEM) onboard the Solar and Heliospheric Observatory (SOHO), a statistical analysis on the excess peak flux (the pre-flare…
AKARI/AcuA Physical Studies of the Cybele Asteroid Family
Hasegawa, Sunao; Usui, Fumihiko; Ootsubo, Takafumi +4 more
We present a study of 107 Cybele asteroids based on the archival database "Asteroid Catalog Using AKARI (AcuA)" taken by the Infrared Astronomical Satellite. The database provides diameters D > 10 km, geometric albedos, and taxonomic information (75%) of the Cybeles. We find taxonomic diversity (mainly C-, D-, and P-type) in the population of 7…
Solar Cycle Variation of Sound Speed inside the Sun
Mullan, D. J.; Rabello-Soares, M. C.; MacDonald, J.
Empirical radial profiles of the changes in sound speed inside the Sun between solar minimum and solar maximum have been extracted from Michelson Doppler Imager data by Baldner & Basu and Rabello-Soares. Here, we compare these results with the theoretical radial profiles predicted by a model of magnetic inhibition of convective onset: In the m…
A new visual - near-infrared diagnostic to estimate the metallicity of cluster and field dwarf stars
Milone, A. P.; Lagioia, E. P.; Bono, G. +3 more
We present a theoretical calibration of a new metallicity diagnostic based on the Strömgren index m1 and on visual - near-infrared (NIR) colors to estimate the global metal abundance of cluster and field dwarf stars. To perform the metallicity calibration we adopt α-enhanced evolutionary models transformed into the observational plane b…
Spatial and Temporal Variations of the Diffuse Iron 6.4 keV Line in the Galactic Center Region
Koyama, Katsuji; Matsumoto, Hironori; Nobukawa, Masayoshi +4 more
We analyzed the diffuse Fe I Kα line generated in the diffuse interstellar molecular hydrogen by primary photons or subrelativistic protons injected by Sagittarius (Sgr) A*. We showed that unlike emission from compact molecular clouds, this emission can be permanently observed in the directions of the Galactic center. We conclude that the diffuse …
Suzaku Observations of Unidentified X-Ray Sources toward the Galactic Bulge
Dotani, Tadayasu; Maeda, Yoshitomo; Ishida, Manabu +2 more
We present Suzaku observations of two unidentified sources towards the Galactic bulge, 1RXS J165256.3
Cosmic Origins Spectrograph Observations of NGC 2024: An Indirect View into the Heart of the Flame
France, Kevin; Snow, Theodore P.; Burgh, Eric B.
As part of a program to study translucent interstellar clouds, NGC 2024 IRS 1 was observed by the Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope. IRS 1 is a heavily reddened B0.5 V star (E(B - V) = 1.69, RV = 4.5, and AV = 7.61) lying outside the core of the NGC 2024 cluster and not considered to be the…
The X-ray Evolution of the Symbiotic Star V407 Cyg during its 2010 Outburst
Nelson, T.; Mukai, K.; Chomiuk, L. +2 more
We present a summary of Swift and Suzaku X-ray observations of the 2010 nova outburst of the symbiotic star, V407 Cyg. The Suzaku spectrum obtained on day 30 indicates the presence of the supersoft component from the white dwarf surface, as well as optically thin component from the shock between the nova ejecta and the Mira wind. The Swift observa…
Probable Identification of the On-disk Counterpart of Spicules in Hinode Ca II H Observations
de Wijn, A. G.
I present a study of high-resolution time series of Ca II H images and Fe I 630.15 nm spectra taken with the Solar Optical Telescope on the Hinode spacecraft. There is excellent correspondence between the Ca II H and the Fe I line core intensity, except tenuous emission around the network field concentrations in the former that is absent in the la…
High-resolution atlas of Rhea derived from Cassini-ISS images
Scholten, F.; Matz, K. -D.; Neukum, G. +7 more
The Cassini Imaging Science Subsystem (ISS) acquired 370 high-resolution images (<500 m/pixel) of Rhea during two close flybys and 9 non-targeted flybys between 2004 and 2010. We combined these images with lower-resolution Cassini images and others taken by the Voyager cameras to produce a high-resolution semi-controlled mosaic of Rhea. This gl…