bluuebunny/crossref_metadata_2025_split huggingface dataset:
Revision of the Selection Function of the Optical Redshift Survey Using the Sloan Digital Sky Survey Early Data Release: Toward an Accurate Estimate of the Source Number Density of Ultra-High Energy Cosmic Rays
Authors: Yoshiguchi Hiroyuki , Nagataki Shigehiro , Sato Katsuhiko , Ohama Nobuyuki , Okamura Sadanori 
Published: March 2014

Abstract
If Ultra-High Energy Cosmic Rays (UHECRs) originate from nearby galaxies, modeling of the distribution of nearby galaxies is important for an accurate estimate of the source number density of UHECRs. We investigate the uncertainty of the selection function of the Optical Redshift Survey (ORS), which we use to construct a source model of UHECRs. The investigation is based on a comparison of the number counts of ORS galaxies with those of the Sloan Digital Sky Survey (SDSS) Early Data Release (EDR). We carefully count galaxies of the same absolute magnitude bin from two samples. We find a slight systematic overestimate of the ORS counts outside $5000 \,\mathrm{km} \,\mathrm{s}^{-1}$ by about a factor of 2, and revise the selection function of the ORS. The revision should be taken into account in any future analysis of the source number density of UHECRs based on the ORS. Using the revised selection function, we determined the global structure of the Local Supercluster (LSC) with a source model of UHECRs consisting of a uniform spherical halo and an exponential disk. We find that the revision is insignificant in terms of the structure of the LSC. However, the revised selection function will be useful for other studies, such as those involving a peculiar velocity and the correlation function.
Radiation Properties of an Accretion Disk with a Non-Zero Torque on Its Inner Edge
Authors: Cao Xinwu , Xu Ya-Di 
Published: March 2014

Abstract
The structure of the inner edge of the accretion disk around a black hole can be altered, if the matter inside the marginally stable orbit is magnetically connected to the disk. In this case, a non-zero torque is exerted on its inner edge, and the accretion efficiency, $\epsilon$, can be much higher than that in the standard accretion-disk model. We explored the radiation properties of an accretion disk at its sonic point around a black hole with a time-steady torque exerted on the inner edge of the disk. The local structure of the accretion flow at the sonic point was investigated in the frame of general relativity. It was found that the accretion flow would be optically thin at its sonic point for most cases, if the additional accretion efficiency $\delta\epsilon$ caused by the torque is as high as $\sim 10\%$. The results imply that a variable torque may trigger transitions of the flow between different accretion types.
Damping and Frequencies of Non-Axisymmetric Trapped g-Mode Oscillations
Authors: Kato Shoji 
Published: March 2014

Abstract
The trapping of non-axisymmetric $g$-mode oscillations in relativistic disks are examined both by a WKB method and by a method of examining the energy flow through the corotation radius. The former is a reexamination of a previous paper to correct an error in the analyses. Both analyses show that the trapped $g$-mode oscillations are damping. We further examine the frequencies and the trapped regions of these oscillations. The fundamental mode and the first overtone are trapped in the innermost region of disks with a moderate ratio of frequencies. They are possible candidates of observed kHz quasi-periodic oscillations.
FTS Measurements of Submillimeter-Wave Atmospheric Opacity at Pampa la Bola: III. Water Vapor, Liquid Water, and 183 GHz Water Vapor Line Opacities
Authors: Matsushita Satoki , Matsuo Hiroshi 
Published: March 2014

Abstract
Further analysis has been made on the millimeter- and submillimeter-wave (100–1600 GHz or 3 mm-188$\, {\mu \mathrm {m}}$) atmospheric opacity data taken with the Fourier Transform Spectrometer (FTS) at Pampa la Bola, 4800 m above the sea level in northern Chile, which is the site of the Atacama Large Millimeter/submillimeter Array (ALMA). Time-sequence plots of millimeter- and submillimeter-wave opacities show similar variations to each other, except for during the periods with liquid water (fog or clouds) in the atmosphere. Using millimeter- and submillimeter-wave opacity correlations under two conditions, which are affected and not affected by liquid water, we succeeded to separate the measured opacity into water vapor and liquid water opacity components. The water vapor opacity shows a good correlation with the 183 GHz water vapor line opacity, which is also covered in the measured spectra. On the other hand, the liquid water opacity and the 183 GHz line opacity show no correlation. Since only the water vapor component is expected to affect the phase of interferometers significantly, and the submillimeter-wave opacity is less affected by the liquid water component, it may be possible to use the submillimeter-wave opacity for a phase correction of submillimeter interferometers.
Spectral Energy Distributions of Dusty Galaxies
Authors: Takagi Toshinobu , Vansevičius Vladas , Arimoto Nobuo 
Published: March 2014

Abstract
We present an SED model of dusty galaxies, in which the equations of radiative transfer were solved by assuming spherical symmetry. The temperature fluctuation of very small dust particles was calculated consistently with the radiative transfer. The adopted dust model consisted of graphite and silicate grains and PAHs, whose relative fractions were determined for each MW, LMC, and SMC-type extinction curve. This model allowed us to derive the intrinsic SEDs of stellar populations embedded in dusty ISM, which are very important indicators for the age of stellar populations. Therefore, the evolutionary phase of starburst galaxies which frequently have very dusty ISM can be investigated with this SED model. We showed that the SED of both Arp 220 and M 82 can be explained by the same single stellar population, despite significant differences in the SED and the infrared luminosity. The apparent difference between their SEDs is mainly caused by the difference in the optical depth. In contrast, the SED of prototypical star-forming ERO, HR 10, indicates that this galaxy is relatively old compared with Arp 220 and M 82. It has been found that, in the case of an optically-thin limit like elliptical galaxies, the optical depth cannot be inferred only from the SED, because of a degeneracy between the optical depth, galactic size, and the spatial distribution of dust; the latter two are important for estimating the average temperature of dust grains in elliptical galaxies. SEDs can be used to constrain the spatial distribution of dust in elliptical galaxies, when the observed size of elliptical galaxies is taken into account.
A Method for the Determination of 3-D Velocity Fields of Disappearing Solar Filaments
Authors: Morimoto Taro , Kurokawa Hiroki 
Published: March 2014

Abstract
The 3-D velocity fields of disappearing filaments (Disparition Brusques: DBs) on the solar disk were extensively studied in order to determine their 3-D velocity fields. Applying Beckers’ cloud model to 5 DB events observed in the $\mathrm{H}\alpha$ line center and $\mathrm{H}\alpha \pm 0.8 \,$Å with the Flare Monitoring Telescope (FMT) at Hida Observatory, we developed a method to derive the complete 3-D velocity field of DBs. The line-of-sight velocity is obtained (i) by calculating the $\mathrm{H}\alpha$ line profile of the filament, and (ii) by measuring the Doppler shift which best fits to the observed temporal variations of contrasts of the filament. The tangential velocity is obtained by tracing the motions of the internal structures on the successive images. In this method, corrections for the effective filter bandwidths of the instrument, stray lights, and Doppler brightening effect are performed. We also discuss the velocity errors which arise from the intrinsic variations of the filament plasma during its activation, the fluctuations in intensities of the background chromosphere, and the choice of different forms of the spread function for estimating the stray light. It is emphasized that the calculation of three-dimensional vector trajectories of a disappearing filament with our method can enhance the quality of a space weather forecast with better certainty.
Plug-In Cryogenic System for Cartridge-Type SIS Receivers
Authors: Yokogawa Sozo , Sekimoto Yutaro , Sugimoto Masahiro , Okuda Takeshi , Sekiguchi Tomohiko , Kamba Toshiaki , Tatematsu Ken’ichi , Nishino Tetsuo , Ogawa Hideo , Kimura Kimihiro , Noda Kazufusa , Narasaki Katsuhiro 
Published: March 2014

Abstract
We developed a cryogenic system, which houses 3 cartridge-type superconductor-insulator-superconductor receivers for millimeter and submillimeter wavelengths. Since it was designed as a prototype receiver of the Atacama Large Millimeter/submillimeter Array (ALMA), high stability, accurate alignment, and easy handling were required. To meet these requirements, the cryogenic system included the following technologies: 1) a thermal link without screws for receiver cartridges; 2) a central support structure to reduce vacuum and gravitational deformation; 3) bellows structures to reduce mechanical vibration of the cryocooler; and 4) a 3-stage Gifford McMahon (GM) cryocooler with an He pot (temperature stabilizer) to reduce the thermal ripple. The cryostat and receiver cartridges are composed of three stages. The temperatures on the 4 K, 12 K, and 100 K stages of the cartridge are 3.5 K, 13.4 K, and 78.3 K, respectively. The thermal conductances of the thermal links showed high performances of $1.7 \,\mathrm{W} \,\mathrm{K}^{-1}$ at the 4 K stage, $5.6 \,\mathrm{W} \,\mathrm{K}^{-1}$ at the 12 K stage, and $3.3 \,\mathrm{W} \,\mathrm{K}^{-1}$ at the 100 K stage. The mechanical vibration on the 4 K stage of the cartridge was reduced to one-tenth, as small as $\approx 2 \, {\mu \mathrm {m}}$ peak-to-peak, compared to that on the 4 K coldhead of the cryocooler, $\approx 20 \, {\mu \mathrm {m}}$ peak-to-peak. The temperature ripple on the cartridge was reduced to as small as 2 mK peak-to-peak, which corresponds to one-seventh of the ripple on the 4 K coldhead with an He pot.
Mapping of the Decameter Radio Sources of Cassiopeia A Using a 100 km Range Long-Baseline Interferometer: Verification of a New Method of Phase Calibration of Interferometers
Authors: Oya Hiroshi , Iizima Masahide 
Published: March 2014

Abstract
A new method is proposed for detecting the phase difference of cesium frequency standards facilitated at coupling stations of an interferometer of 100 km range baselines for observations of decameter wavelength radio waves. In this method, the Earth’s rotation is utilized. That is, a time-depending variation of the phase differences of arriving radio waves from a given source forms a so-called fringe function due to the Earth’s rotation. By generating a reference fringe function corresponding to the position of a selected radio source, the signals can be detected being selected from widely and continuously distributed radio sources in the sky, when the correlation is analyzed between the generated reference fringe function and the fringe data detected by the interferometer. The feasibility of the proposed method has been verified by applying the method to observations of a 100 km range baseline interferometer for decameter wavelength radio waves at Tohoku University selecting the radio-wave sources in the Cassiopeia A supernova remnant as the objective. The results of the analyzed correlation values averaged for the observation data of 30 hr, at 22.158 MHz, are determined being scattered around average values with a distribution of less than 25%; this distribution corresponds to a phase determination error of $\pm 12^\circ$ for the cesium frequency standards of the interferometer at 10 MHz. That is, we can calibrate the phase shift of the cesium frequency standards facilitated at each member station of the interferometer system with an accuracy of $\pm 12^\circ$, which corresponds to an accuracy of $\pm 1 ''$ for determining the direction of the radio-source position in the sky in the case of 100 km range long baseline interferometer. This accuracy is, however, only possible when an integration time longer than 30 hr is applied for analyses of the fringe correlation values.
ASCA Observation of Unusually X-Ray-Hard Radio-Quiet QSO Kaz102
Authors: Takamitsu MIYAJI , Ishisaki Yoshitaka , Ueda Yoshihiro , Ogasaka Yasushi , Awaki Hisamitsu , Hayashida Kiyoshi 
Published: March 2014

Abstract
We observed the radio-quiet QSO Kaz102 $(z = 0.136)$ with ASCA as a part of our program for a complete spectral characterization of hard X-ray selected AGNs. We found that Kaz102 shows unusual spectral properties. A simple power-law with absorption in our Galaxy gave a satisfactory description of the spectrum. However, it showed a very hard photon index of $\Gamma \sim 1.0$ with no sign of deep absorption or a prominent spectral feature. We further explored the Compton reflection with the Fe $\mathrm{K}\alpha$ line and warm absorber models for hardening the spectra. Both gave statistically satisfactory fits. However, the Compton reflection model requires a very low metal abundance (0.03–0.07 in solar units). The warm absorber model with no direct component is preferred, and gave a very high ionization parameter of $\xi \sim 10^{2.3}$. If this is the case, the values of $\xi$, warm absorber column density, and variability over $\sim 10\;\mathrm{yr}$ may suggest that the warm absorber resides in the broad-line region and crosses the line of sight to the central X-ray source.
A New Candidate for the Dark Group of Galaxies, RX J0419 $+$0225
Authors: Kawaharada Madoka , Makishima Kazuo , Takahashi Isao , Nakazawa Kazuhiro , Matsushita Kyoko , Shimasaku Kazuhiro , Fukazawa Yasushi , Xu Haiguang 
Published: March 2014

Abstract
The bright extended X-ray source RX J0419$+$0225, first discovered in the ROSAT All Sky Survey and identified with an S0 galaxy NGC 1550, was observed with ASCA for 48 ks in 1999 August. The detected diffuse X-ray emission is centered at NGC 1550, whose redshift is 0.0123, extending out to at least $15'$, or $210 \,h^{-1}_{75} \,\mathrm{kpc}$, where $h_{75}$ is the Hubble constant in units of $75 \,\mathrm{km} \,\mathrm{s}^{-1} \,\mathrm{Mpc}^{-1}$. The X-ray surface brightness is represented by a $\beta$ model with ${\beta \simeq 0.47}$ and a core radius of $15 \pm 1 \,h^{-1}_{75} \,\mathrm{kpc}$. The temperature and 1–10 keV X-ray luminosity (up to $15'$) of this system were measured as being 1.4 keV and $4.7 \times 10^{42} \,h^{-2}_{75} \,\mathrm{erg} \,\mathrm{s}^{-1}$, respectively. There is no strong evidence of a temperature gradient. Within a radius of $210 \,h^{-1}_{75} \,\mathrm{kpc}$, the estimated total mass of the system becomes $1.5\times 10^{13} \,h^{-1}_{75} \,{{{M}_{\odot}}}$, which is typical of a galaxy group. With the optical information currently available, there are only two other faint galaxies. Including their B-band luminosity, the mass-to-light ratio of the system comes to $\sim 400 \,h_{75} \,{{{M}_{\odot}}}/{{{L}_{\odot}}}$, which is comparable to those of galaxy clusters. Therefore, RX J0419$+$0225 can be regarded as a “dark group candidate” in that it has an unusually high mass-to-light ratio for its optical luminosity. This object is one of the nearest among those ever identified as such candidates.
Period Change of Superhumps in a WZ Sge-Type Dwarf Nova, HV Virginis
Authors: Ishioka Ryoko , Kato Taichi , Uemura Makoto , Pietz Jochen , Vanmunster Tonny , Krajci Tom , Torii Ken’ichi , Tanabe Kenji , Kiyota Seiichiro , Kinugasa Kenzo , Masi Gianluca , Morikawa Koichi , Cook Lewis M. , Schmeer Patrick , Yamaoka Hitoshi 
Published: March 2014

Abstract
After 10 years of quiescence, HV Vir underwent a superoutburst in 2002 January. We report on time-series observations that clearly reveal the period change of ordinary superhumps during the superoutburst. We derived a mean superhump period of 0.058260 d and a positive period derivative of $7 \times 10^{-5}$. These results are in good agreement with a value obtained from the 1992 superoutburst. We also detected early superhumps, which were not clearly recognized in the past outburst, and a possible rebrightening. Both of them are common characteristics of WZ Sge-type stars.
New Results from ASCA on the Type II Bursts of the Rapid Burster (MXB 1730$-$335)
Authors: Mahasena Putra , Inoue Hajime , Asai Kazumi , Dotani Tadayasu 
Published: March 2014

Abstract
Type II burst properties of the Rapid Burster have been studied with the X-ray astronomy satellite ASCA. To study spectral evolutions throughout a burst cycle from the onset of a burst to the next burst, we constructed six composite burst-cycles in terms of the burst fluence, and divided each of them into seven phases. We then fitted the 42 spectra with a two-component model consisting of a blackbody (BB) component expected from the boundary layer, and a multi-color-disk (MCD) component expected from the standard disk, systematically. The results show that the luminosity of the BB component is much larger than that of the MCD component during a burst, while the two luminosities become comparable during a persistent phase. They also indicate that the innermost radius of the standard disk tends to recede outwards in the burst decay. These results suggest that although the standard disk extends close to the neutron star surface during a persistent phase, another accretion flow onto the neutron star is needed during a burst phase. We argue that an advection-dominated accretion flow (ADAF) would be a dominant flow onto the neutron star during a burst, and that a limit cycle of the accretion flow between an ADAF and a standard disk can explain the overall properties of the type II bursts.
Acceleration Method of Neighbor Search with GRAPE and Morton Ordering
Authors: Saitoh Takayuki R. , Koda Jin 
Published: March 2014

Abstract
We describe a new method to accelerate neighbor searches on GRAPE, i.e. a special-purpose hardware that efficiently calculates the gravitational forces and potentials in $N$-body simulations. In addition to gravitational calculations, GRAPE simultaneously constructs lists of neighbor particles that are necessary for Smoothed Particle Hydrodynamics (SPH). However, the data transfer of the neighbor lists from GRAPE to the host computer is time-consuming, and can be a bottleneck. In fact, the data transfer can take about the same time as the calculations of the force themselves. Making use of GRAPE’s special treatment of neighbor lists, we can reduce the amount of data transfer if we search neighbors in the order that the neighbor lists, constructed in a single GRAPE run, overlap each other. We find that the Morton ordering requires very low additional calculation and programming costs, and results in successful speed-up on data transfer. We show some benchmark results in the case of GRAPE-5. Typical reduction in transferred data becomes as much as 90%. This method is suitable not only for GRAPE-5, but also for GRAPE-3 and the other versions of GRAPE.
First Fringe Detection with VERA’s Dual-Beam System and Its Phase-Referencing Capability
Authors: Honma Mareki , Fujii Takahiro , Hirota Tomoya , Horiai Koji , Iwadate Kenzaburo , Jike Takaaki , Kameya Osamu , Kamohara Ryuichi , Kan-ya Yukitoshi , Kawaguchi Noriyuki , Kobayashi Hideyuki , Kuji Seisuke , Kurayama Tomoharu , Manabe Seiji , Miyaji Takeshi , Nakashima Kouichirou , Omodaka Toshihiro , Oyama Tomoaki , Sakai Satoshi , Sakakibara Sei-ichiro , Sato Katsuhisa , Sasao Tetsuo , Shibata Katsunori M. , Shimizu Rie , Suda Hiroshi , Tamura Yoshiaki , Ujihara Hideki , Yoshimura Akane 
Published: March 2014

Abstract
We present the results of the first dual-beam observations with VERA (VLBI Exploration of Radio Astrometry). The observations of a pair of $\mathrm{H}_2\mathrm{O}$ maser sources, W 49N and OH 43.8$-$0.1, were carried out on 2002 May 29 and July 23, and fringes of the $\mathrm{H}_2\mathrm{O}$ maser lines at 22 GHz were successfully detected. While the residual fringe phases of both sources showed rapid variations over $360^\circ$ due to the atmospheric fluctuation, the differential phase between the two sources remained constant for 1 hour with an r.m.s. of $8^\circ$, demonstrating that the atmospheric phase fluctuation was effectively removed by dual-beam phase referencing. An analysis based on the Allan standard deviation reveals that the differential phase is mostly dominated by white phase noise, and the coherence function calculated from the differential phase shows that after phase referencing the fringe visibility can be integrated for an arbitrarily long time. These results demonstrate VERA’s high capability of phase referencing, indicating that it is a promising tool for phase-referencing VLBI astrometry at $10 \,\mu\mathrm{as}$-level accuracy.
A Differential Abundance Analysis of the Wide Binary Pair HD 219542 A and B
Authors: Sadakane Kozo , Ohkubo Michiko , Honda Satoshi 
Published: March 2014

Abstract
The abundances of 22 elements (Li through Zr) in the A and B components of the visual pair HD 219542 were determined and compared using a differential analysis technique. Both components were found to be metal rich, $[\mathrm{Fe/H}] = +0.13$, in the brighter component (A) and $[\mathrm{Fe/H}] = +0.08$ in the fainter component (B). The abundances of three elements (Sc, Ti, and Fe) are definitely higher (by 0.05 dex) in component A than in component B. On the other hand, both components have nearly identical abundances of the light element Si. No evidence has been found for differences in the abundances for C, O, Na, Mg, Al, S, Ca, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, and Zr. No clear correlation has been found between the differences in the abundance between the two components and the condensation temperature ($T_\mathrm{c}$).
Variability and Beaming of GeV Gamma-Ray-Loud Blazars
Authors: Xie Guang-Zhong , Ma Li , Zhou Shu-Bai , Chen Luo-En , Xie Zhao-Hua 
Published: March 2014

Abstract
Considering the Klein–Nishina effects for high-energy $\gamma$-ray emissions, we derived a corrected form of the basic Elliot–Shapiro formula. Two new lower limits to the time scales of the variability expected from an accreting Schwarzschild black hole and Kerr black hole were derived, respectively. For a sample of 25 GeV $\gamma$-ray-loud blazars known to have the shortest time scales of flux variability, $t_\mathrm{min}$, we studied the corrected Elliot–Shapiro relations between $t_\mathrm{min}$ and the GeV $\gamma$-ray luminosities in both the high and low states, respectively. We observe that: (1) No sources have been observed to have GeV $\gamma$-ray luminosities in the low state above the corrected Eddington limit being produced by a Kerr black hole and a Schwarzschild black hole. (2) Only one source has been observed to have a luminosity in the high state above the corrected Eddington limit being produced by a Kerr black hole and a Schwarzschild black hole, which is a new argument for not invoking relativistic beaming models for the present EGRET observational data alone. Our conclusion is that if one considers the Klein–Nishina effect, the evidence for beamed emission from the present gamma-ray data alone is weak. Obviously, our conclusion is consistent with that of Dermer and Gehrels (1995, ApJ, 447, 103), but it is a new independent evidence.