234 research outputs found
Formation of Nanometer-Thick Water Layer at High Humidity on Dynamic Crystalline Material Composed of Multi-Interactive Molecules
Crystalline powders self-assembled from interactive discrete molecules reversibly transformed from a porous structure to a 2D one with a nanometer-thick H2O layer by hydration/dehydration. Multi-point weak intermolecular interactions contributed to maintenance of each phase. This structure transformation induced a humidity-dependent ion conductivity change from insulator to 3.4 x 10(-3) S cm(-1).open1122sciescopu
Hemispherical confocal imaging using turtleback reflector
We propose a new imaging method called hemispherical confocal imaging to clearly visualize a particular depth in a 3-D scene. The key optical component is a turtleback reflector which is a specially designed polyhedral mirror. By combining the turtleback reflector with a coaxial pair of a camera and a projector, many virtual cameras and projectors are produced on a hemisphere with uniform density to synthesize a hemispherical aperture. In such an optical device, high frequency illumination can be focused at a particular depth in the scene to visualize only the depth with descattering. Then, the observed views are factorized into masking, attenuation, and texture terms to enhance visualization when obstacles are present. Experiments using a prototype system show that only the particular depth is effectively illuminated and hazes by scattering and attenuation can be recovered even when obstacles exist.Microsoft ResearchJapan Society for the Promotion of Science (Grants-in-Aid For Scientific Research 21680017)Japan Society for the Promotion of Science (Grants-in-Aid For Scientific Research 21650038
Detection of Excess Hard X-ray Emission from the Group of Galaxies HCG62
From the group of galaxies HCG62, we detected an excess hard X-ray emission
in energies above keV with \A SCA. The excess emission is spatially
extended up to from the group center, and somewhat enhanced toward
north. Its spectrum can be represented by either a power-law of photon index
0.8-2.7, or a Bremsstrahlung of temperature keV. In the 2-10 keV range,
the observed hard X-ray flux, erg cm
s, implies a luminosity of erg s for a
Hubble constant of 50 km s Mpc. The emission is thus too luminous
to be attributed to X-ray binaries in the memb er galaxies. We discuss possible
origin of the hard X-ray emission.Comment: 6 pages, 3 Postscript figures, uses emulateapj.sty. Accepted for
publication in the Astrophysical Journal Letter
Suzaku observations of the Hydra A cluster out to the virial radius
We report Suzaku observations of the northern half of the Hydra A cluster out
to ~1.4 Mpc, reaching the virial radius. This is the first Suzaku observations
of a medium-size (kT ~3 keV) cluster out to the virial radius. Two observations
were conducted, north-west and north-east offsets, which continue in a filament
direction and a void direction of the large-scale structure of the Universe,
respectively. The X-ray emission and distribution of galaxies elongate in the
filament direction. The temperature profiles in the two directions are mostly
consistent with each other within the error bars and drop to 1.5 keV at 1.5
r_500. As observed by Suzaku in hot clusters, the entropy profile becomes
flatter beyond r_500, in disagreement with the r^1.1 relationship that is
expected from accretion shock heating models. When scaled with the average
intracluster medium (ICM) temperature, the entropy profiles of clusters
observed with Suzaku are universal and do not depend on system mass. The
hydrostatic mass values in the void and filament directions are in good
agreement, and the Navarro, Frenk, and White universal mass profile represents
the hydrostatic mass distribution up to ~ 2 r_500. Beyond r_500, the ratio of
gas mass to hydrostatic mass exceeds the result of the Wilkinson microwave
anisotropy probe, and at r_100, these ratios in the filament and void
directions reach 0.4 and 0.3, respectively. We discuss possible deviations from
hydrostatic equilibrium at cluster outskirts. We derived radial profiles of the
gasmass- to-light ratio and iron-mass-to-light ratio out to the virial radius.
Within r_500, the iron-mass-to-light ratio of the Hydra A cluster was compared
with those in other clusters observed with Suzaku.Comment: 16 pages, 15 figures; Accepted for publication in PAS
Suzaku Observation of HCG 62: Temperature, Abundance, and Extended Hard X-ray Emission Profiles
We present results of 120 ks observation of a compact group of galaxies
HCG~62 () with Suzaku XIS and HXD-PIN\@. The XIS spectra for four
annular regions were fitted with two temperature {\it vapec} model with
variable abundance, combined with the foreground Galactic component. The
Galactic component was constrained to have a common surface brightness among
the four annuli, and two temperature {\it apec} model was preferred to single
temperature model. We confirmed the multi-temperature nature of the intra-group
medium reported with Chandra and XMM-Newton, with a doughnut-like high
temperature ring at radii 3.3--6.5 in a hardness image. We found Mg, Si, S,
and Fe abundances to be fairly robust. We examined the possible
``high-abundance arc'' at southwest from the center, however Suzaku
data did not confirm it. We suspect that it is a misidentification of an excess
hot component in this region as the Fe line. Careful background study showed no
positive detection of the extended hard X-rays previously reported with ASCA,
in 5--12 keV with XIS and 12--40 keV with HXD-PIN, although our upper limit did
not exclude the ASCA result. There is an indication that the X-ray intensity in
region is % higher than the nominal CXB level (5--12 keV),
and Chandra and Suzaku data suggest that most of this excess could be due to
concentration of hard X-ray sources with an average photon index of
. Cumulative mass of O, Fe and Mg in the group gas and the
metal mass-to-light ratio were derived and compared with those in other groups.
Possible role of AGN or galaxy mergers in this group is also discussed.Comment: 29 pages with 9 figures, accepted for publication in PASJ Vol 60,
second Suzaku special issu
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