bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of the Polarization of Photon Splitting on the Cyclotron Lines in Large-Scale Atmospheres with Super-Strong Magnetic Fields
Authors: Nishimura Osamu 
Published: March 2014

Abstract
The cyclotron lines are affected by photon splitting in super-strong magnetized atmospheres ($ \sim 4.4 \times 10^{13} \,\mathrm{G}$) into which a power-law-type flux is injected. We studied the polarization effect of photon splitting on the cyclotron line formation by treating different modes of splitting. We calculated the emergent spectra for two conditions: only one splitting mode and three splitting modes that could operate in a neutron-star atmosphere with a subcritical magnetic field. Photon splitting can also operate over a larger scale than cyclotron resonant scattering in a neutron-star atmosphere, since photon splitting occurs in a super-strong magnetic field even in the absence of a plasma. We therefore considered atmospheres consisting of lower and higher density regions. Cyclotron resonant scattering is dominant in a higher density region, and photon splitting is dominant in a lower density region. In three splitting modes, we found that the cyclotron absorption lines are strongly reprocessed by photon splitting, and thus may not be detected even for a magnetic field of about $ 1.0 \times 10^{13} \,\mathrm{G}$ in the power-law-type spectra. However, we confirmed that the cyclotron absorption lines are not mostly reprocessed by photon splitting in only one splitting mode.
CISCO: Cooled Infrared Spectrograph and Camera for OHS on the Subaru Telescope
Authors: Motohara Kentaro , Iwamuro Fumihide , Maihara Toshinori , Oya Shin , Tsukamoto Hiroyuki , Imanishi Masatoshi , Terada Hiroshi , Goto Miwa , Iwai Jun’ichi , Tanabe Hirohisa , Hata Ryuji , Taguchi Tomoyuki , Harashima Takashi 
Published: March 2014

Abstract
This paper describes a Cooled Infrared Spectrograph and Camera for OHS (CISCO), mounted on the Nasmyth focus of the Subaru telescope. It is primarily designed as a back-end camera of the OH-Airglow Suppressor (OHS), and is also used as an independent, general-purpose near-infrared camera/spectrograph. CISCO is based on a single $ 1024 \times 1024$ format HgCdTe HAWAII array detector, and is capable of either wide-field imaging of $ {1\rlap {.}{}^{\mathrm {\prime }}8} \times {1\rlap {.}{}^{\mathrm {\prime }}8}$ field-of-view or low-resolution spectroscopy from 0.9 to 2.4 $ {\mu \mathrm {m}}$. The limiting magnitudes measured during test observations were found to be $ J=23.5 \,\mathrm{mag}$ and $ K^{\prime} = 22.4 \,\mathrm{mag}$ (imaging, $ {1{}^{\mathrm {\prime \prime }}}$ aperture, $ \mathrm{S} / \mathrm{N} = 5 $, 1 hr exposure).
Search for Hot Gas in the Local Group with ASCA
Authors: Osone Satoko , Makishima Kazuo , Matsuzaki Keiichi , Ishisaki Yoshitaka , Fukazawa Yasushi 
Published: March 2014

Abstract
An X-ray study was made to examine whether some part of the soft X-ray background is coming from hot gas in the Local Group. For this purpose, four consecutive pointings were made with ASCA toward a sky region between M31 and M33, which is close to the direction of the center of the Local Group. By comparing the X-ray surface brightness in this sky direction with that in another blank sky region near the north equatorial pole, an upper limit on any soft excess X-ray background was determined to be $2.8 \times 10^{-9} \,\mathrm{erg} \,\mathrm{cm}^{-2} \,\mathrm{s}^{-1} \,\mathrm{sr}^{-1}$ with a 90% confidence level statistical error. Assuming an optically-thin thermal bremsstrahlung energy spectrum (Raymond–Smith model) for a temperature of 1 keV and a $\beta$-model electron density distribution for a core radius of 100 kpc for the X-ray halo, the upper limit of the central plasma density was obtained to be $1.3 \times 10^{-4} \,\mathrm{cm}^{-3}$. The plasma column density is too low to contribute significantly to the observed quadrupole anisotropy in the cosmic microwave background.
Tridimensional Spectroscopic Observation of the Interacting System NGC 7592
Authors: Hattori Takashi , Yoshida Michitoshi , Ohtani Hiroshi , Ishigaki Tsuyoshi , Sugai Hajime , Hayashi Tadashi , Ozaki Shinobu , Ishii Motomi 
Published: March 2014

Abstract
We performed a tridimensional spectroscopic study of NGC 7592, an infrared-luminous interacting system of three galaxies, one of which contains a Seyfert 2 nucleus. Narrow-band images of $\mathrm{H}\alpha$ and [O iii] were obtained using an imaging Fabry–Perot interferometer with a tunable filter. An area-spectroscopic observation was also made by a slit scan in a direction perpendicular to the slit. The Seyfert nucleus was found to be surrounded by a knotty star-forming region of disk- or ring-shape. Along the axis of the disk or ring, a highly-ionized bipolar gaseous region was identified. From kinematical analyses, it has been suggested that this system is composed of two galaxies; one apparent nucleus is considered to be a giant H ii region belonging to one galaxy. This result is supported by the morphological properties in near-infrared. Further, it has been suggested that one galaxy is an early-type spiral, whereas the other is a late-type one, and the two galaxies show a marked difference in the distribution of the star-forming regions within each. The cause of the difference was argued in relation with the dynamical perturbation between the two galaxies.
Modeling a Pairwise Peculiar Velocity Distribution Function of Dark Matter from Halo Density Profiles
Authors: Kuwabara Takeshi , Taruya Atsushi , Suto Yasushi 
Published: March 2014

Abstract
We derive the pairwise peculiar velocity distribution function of dark matter particles by applying a dark-matter halo approach. Unlike previous work, we do not assume a Gaussian velocity distribution function of dark matter in a single halo, but compute it self-consistently with the assumed density profile for the dark-matter halo. The resulting distribution function is well approximated by an exponential distribution which is consistent with the previous observational, numerical, and theoretical results. We also compute the pairwise peculiar velocity dispersion for different density profiles, and provide a practical fitting formula. We apply an empirical biasing scheme into our model and present a prediction for a pairwise peculiar velocity dispersion of galaxies, and reproduce the previous results of simulations using our semi-analytical method.
Composite Luminosity Functions Based on the Sloan Digital Sky Survey “Cut and Enhance” Galaxy Cluster Catalog
Authors: Goto Tomotsugu , Okamura Sadanori , Mckay Timothy A. , Bahcall Neta A. , Annis James , Bernardi Mariangela , Brinkmann Jonathan , Gómez Percy L. , Hansen Sarah , Kim Rita S. J. , Sekiguchi Maki , Sheth Ravi K. 
Published: March 2014

Abstract
We present here results on the composite luminosity functions (LF) of galaxies in the clusters of galaxies selected from the Cut and Enhance cluster catalog (CE) of the Sloan Digital Sky Survey. We constructed composite LFs in the five SDSS bands, $u, g, r, i$, and $z$, using 204 CE clusters ranging from $z = 0.02$ to $z = 0.25$ . Background and foreground galaxies were subtracted from the LF using an annular region around clusters to take large-scale, galaxy-number-count variances into consideration. A LF of each cluster was weighted according to the richness and number of contributing galaxies to construct the composite LF. Taking advantage of accurate photometry of SDSS, we used photometric redshifts to construct composite luminosity functions and thus study a large number of clusters. The robustness of the weighting scheme was tested using a Monte-Carlo simulation. The best-fit Schechter parameters are $(M^*, \alpha) = (-21.61 \pm 0.26,-1.40 \pm0.11), (-22.01 \pm 0.11,-1.00 \pm 0.06), (-22.21 \pm 0.05,-0.85 \pm 0.03), (-22.31 \pm 0.08,-0.70 \pm 0.05)$, and $(-21.36 \pm 0.06,-0.58 \pm 0.04)$ in $u, g, r, i$, and $z$, respectively. We find that the slope of composite LFs becomes flatter toward a redder color band. Compared with the field LFs of the SDSS, the cluster LFs have brighter characteristic magnitude and flatter slopes in the $g, r, i$, and $z$ bands. These results are consistent with the hypothesis that the cluster LF has two distinct underlying populations; i.e. the bright end of the LF is dominated by bright early types that follow a Gaussian-like luminosity distribution, while the faint-end of the cluster LF is a steep power-law like function dominated by star-forming (bluer) galaxies. We also studied the composite LFs for early-type and late-type galaxies using profile fits, a concentration parameter and $u-r$ color to classify galaxy morphology. A strong dependence of LF on galaxy morphology was found. The faint end slope of the LF is always flatter for early-type galaxies than late-type, regardless of the passband and methodology. These results are consistent with the hypothesis that the cluster regions are dominated by bright elliptical galaxies. This work also provides a good low-redshift benchmark for on-going multi-color photometric studies of high redshift clusters of galaxies using 4–8m class telescopes.
Extended Thermal X-Ray Emission from the Spiral-Dominant Group of Galaxies HCG 57
Authors: Fukazawa Yasushi , Kawano Naomi , Ohto Akimitsu , Mizushima Hirofumi 
Published: March 2014

Abstract
We observed a group of galaxies, HCG 57, with ASCA. Regardless that their member galaxies are dominated by spiral galaxies, we detected extended thermal X-ray emission that is attributed to hot gas with a temperature of $1.04\pm0.10 \,\mathrm{keV}$. This is the second clear detection of thermal X-ray emission from a spiral-dominant group of galaxies after HCG 92. The luminosity of the thermal emission is about $5\times10^{41} \,\mathrm{erg} \,\mathrm{s}^{-1}$ in the 0.5–10 keV band, which is higher than that of HCG 92, but relatively less luminous among groups of galaxies. The X-ray emission is extended over several member galaxies, and is thus associated with the group rather than an individual galaxy. The metal abundance cannot be well constrained with a lower limit of 0.08 solar. The gas-to-stellar mass ratio is $\sim0.3$. Although this is relatively low among groups, the hot gas is also a significant component even in the spiral-dominant group. We suggest that the X-ray faintness of spiral-dominant groups is due to the low surface brightness and somewhat low gas mass, at least in the case of HCG 57.
Extended Deep Minimum and Subsequent Brightening of RX And in 1996-1997
Authors: Kato Taichi , Nogami Daisaku , Masuda Seiji 
Published: March 2014

Abstract
We discovered that RX And, one of the prototypical Z Cam-type dwarf novae, underwent a deep, extended faint state in 1996–1997. Time-resolved photometry at the bottom of the fading revealed the presence of strong flickering, and the absence of detectable orbital modulation. This finding indicates that mass-transfer remained even at the deepest minimum of the fading, contrary to what was observed in a deep minimum of a VY Scl-type star, MV Lyr. RX And subsequently underwent a brightening (outburst) during its recovery stage. The photometric and spectroscopic characteristics of the brightening significantly differed from those of ordinary outbursts of RX And, and are considered to resemble an inside-out type outburst of a long-period dwarf nova. An examination of historical visual observations revealed the possible presence of $\sim 10{-}\mathrm{yr}$ periodicity, which is close to what has been proposed for MV Lyr. The common observed features between RX And and VY Scl-type stars may suggest a common underlying mechanism for producing temporary deep fadings. A departure from the disk instability model, as observed in VY Scl-type stars, was not apparent in the present fading of RX And. In conjunction with a recently published Hubble Space Telescope observation during the same fading, we can conclude that the phenomenological difference from the VY Scl-type fading can be understood to be a smaller effect of irradiation on the accretion disk in RX And.
Advection-Dominated Accretion Flow in the Kerr Metric: Propagation of a Wave Pattern
Authors: Musil Tomáš , Karas Vladimír 
Published: March 2014

Abstract
The time evolution of an advection-dominated accretion flow is explored in terms of relativistic fluid equations. An axially symmetric, vertically averaged mean flow is constructed and perturbed. An axisymmetric pattern is followed as it propagates in the form of a wave towards the horizon of a rotating black hole. Several assumptions are relaxed in comparison with previous works (Manmoto et al. 1996, AAA 65.067.206). The wave reflection and steepening are examined and the influence of black hole angular momentum is discussed.
Three-Dimensional Genus Statistics of Galaxies in the SDSS Early Data Release
Authors: Hikage Chiaki , Suto Yasushi , Kayo Issha , Taruya Atsushi , Matsubara Takahiko , Vogeley Michael S. , Hoyle Fiona , Gott J. Richard , Brinkmann Jon ,   for the SDSS collaboration
Published: March 2014

Abstract
We present the first analysis of three-dimensional genus statistics for the SDSS EDR galaxy sample. Due to the complicated survey volume and the selection function, analytic predictions of the genus statistics for this sample are not feasible; therefore, we construct extensive mock catalogs from $ N$-body simulations in order to compare the observed data with model predictions. This comparison allows us to evaluate the effects of a variety of observational systematics on the estimated genus for the SDSS sample, including the shape of the survey volume, the redshift distortion effect, and the radial selection function due to the magnitude limit. The observed genus for the SDSS EDR galaxy sample is consistent with that predicted by simulations of a $ \Lambda$-dominated spatially-flat cold dark matter model. Standard ($ \Omega_0=1$) cold dark matter model predictions do not match the observations. We discuss how future SDSS galaxy samples will yield improved estimates of the genus.
Near-Infrared Observations of the IRAS/SiO Sources in the Galactic Bulge: a Large Scale Distribution
Authors: Deguchi Shuji , Fujii Takahiro , Nakashima Jun-ichi , Wood Peter R. 
Published: March 2014

Abstract
Near-infrared photometric observations in the $ J$-, $ H$-, and $ K$-bands were made for 120 IRAS sources toward the Galactic bulge ($-10^{\circ} &lt; l &lt; 15^{\circ}$ and $ \vert b\vert &lt; 3^{\circ}$, excluding $ \vert l\vert &lt; 3^{\circ}$). They are well-confirmed, mass-losing late-type stars having accurate radial velocities derived from SiO maser observations. For 118 sources, single, unambiguous near-infrared counterparts were found within the errors of the IRAS/MSX positions; and for the other 2 sources, faint candidates only detectable in the $ K$-band were found. From the $ J$-, $ H$-, $ K$-band and IRAS 12 and 25$\, {\mu \mathrm {m}}$ intensities, we estimated the spectral energy distributions of the sources, and obtained distances assuming a constant intrinsic luminosity. Adding all of the distance data of the IRAS/SiO sources in $-10^{\circ} &lt; l &lt; 25^{\circ}$ published in previous papers, we mapped the positions of 272 sampled stars onto the Galactic plane. The map clearly shows a bar structure, where the major axis of the bar is oriented $ 22^{\circ}(\pm 8^{\circ}$) from the Sun-Galactic center line. We also reanalyzed the radial-velocity shift with the distance in this sample. These analyses suggest that the data are consistent with the current bar theory of the Galactic bulge.
Note on the “Dead Zone” in Layered Accretion Models
Authors: Huré Jean-Marc 
Published: March 2014

Abstract
Current layered accretion models neglect the properties of the “dead zone”. However, as argued here from simple considerations, the thickness of this zone is a critical quantity when the disc is in hydrostatic equilibrium. It controls not only the structure of the superficial, active layers, but also the mid-plane density and the total disc mass, and should therefore be introduced in models of that kind, steady or not. But in the absence of intrinsic heating, the dead zone must have a tiny size which, given the non-stationary and turbulent character of the global flow, makes very likely its mixing together with the two active layers.
Superhumps of CC Cancri Revisited
Authors: Kato Taichi , Uemura Makoto , Ishioka Ryoko , Pietz Jochen 
Published: March 2014

Abstract
We observed the 2001 November superoutburst of CC Cnc. This observation represents the first detailed coverage of a superoutburst of this object. The best-determined mean superhump period is $0.075518 \pm 0.000018 \,\mathrm{d}$, which is 2.7% longer than the reported orbital period. This fractional superhump excess is a quite typical value for a normal SU UMa-type dwarf nova, excluding the previously raised possibility that CC Cnc may have an anomalously large fractional superhump excess. During the superoutburst plateau, the object showed a decrease of the superhump period at $\dot{P}/P =-10.2 \pm 1.3 \times 10^{-5}$, which is one of the largest negative period derivatives known in all SU UMa-type dwarf novae.
Photometric Study of KR Aurigae during the High State in 2001
Authors: Kato Taichi , Ishioka Ryoko , Uemura Makoto 
Published: March 2014

Abstract
We photometrically observed the VY Scl-type cataclysmic variable KR Aurigae after its final rise from a fading episode in 2000–2001. A time-resolved observation revealed that the light curve is dominated by a persistent short-term variation with time-scales of minutes to tens of minutes. On some nights, quasi-periodic variations with periods of 10–15 min were observed. No coherent variation was detected. The power spectral density of the variation has a power-law component ($f^{-1.63}$). The temporal properties of the short-term variations in KR Aur present additional support for the possibility that flickering in CVs may be better understood as the result of a self-organized critical state, as in black-hole candidates. The light curve lacks “superhump”-type signals, which are relatively frequently seen in VY Scl-type systems and which are suggested to arise from a tidal instability of the accretion disk induced by changing mass-transfer rates. The present observation suggests a borderline of superhump excitation in VY Scl-type stars between mass ratios of $q = 0.43$ (MV Lyr) and $q = 0.60$ (KR Aur).
Subaru/HDS Study of the Extremely Metal-Poor Star CS 29498-043: Abundance Analysis Details and Comparison with Other Carbon-Rich Objects
Authors: Aoki Wako , Norris John E. , Ryan Sean G. , Beers Timothy C. , Ando Hiroyasu 
Published: March 2014

Abstract
We report on the details of an abundance study using the Subaru Telescope High Dispersion Spectrograph for the extremely metal-poor ($[\mathrm{Fe/H}] =-3.75$) star CS 29498-043, whose overabundances of C, N, Mg, and Si were reported in our previous work. The effect of the large overabundance of Mg found in this object on the stellar atmosphere is included in the abundance analysis. We also performed a similar analysis for the other eight carbon-rich, metal-poor ($-2.7 &lt; [\mathrm{Fe/H}] &lt;-1.9$) stars with excesses of $s$-process elements, and for the carbon-rich object CS 22957-027 which shows no excess of neutron-capture elements. Neutron-capture elements in CS 29498-043, as well as CS 22949-037 which is also known to have large excesses of C, N, Mg, and Si, do not show any overabundance. This fact clearly distinguishes these two stars from other carbon-rich objects with excesses of $s$-process elements. The abundances of Mg, Al, and Si in CS 29498-043 and CS 22949-037 are significantly higher than those in other carbon-rich objects and non-carbon-rich stars with similar metallicities. The abundance nature of these two stars suggests the existence of a class of extremely metal-poor stars with large excesses of C, N, Mg, Al, and Si, which presumably originate from supernovae in which relatively little material escaped from the iron core.
Long-Term X-Ray Variability of Quasars in the Lockman Hole Field Observed with ROSAT
Authors: Ezoe Yu-ichiro , Iyomoto Naoko , Makishima Kazuo , Hasinger Günter 
Published: March 2014

Abstract
An improved method has been utilized to estimate the X-ray power spectral densities (PSD) and the variation time scales of three quasars in the Lockman Hole field. Five archival ROSAT PSPC data covering a two-year range were analyzed. To estimate PSD from sparse and unevenly-sampled lightcurves, a forward-method approach with extensive Monte Carlo simulations was adopted. A broken power-law type PSD with a constant Poisson noise component was assumed with a break frequency, $f_\mathrm{b}$. Then, assuming the PSD slope, $\alpha$, to be $-2 &lt; \alpha &lt;-1, 1/ f_\mathrm{b}$ was constrained as $\gtrsim$ 25 days for one object, while the constraints on the other two objects were very weak. The long-time scale of the one object is consistent with the view that luminous AGNs host massive black holes.
Optical Imaging of the Radiant Points of Leonids during the 2001 Storm with the 105 cm Kiso Schmidt Telescope
Authors: Nishiura Shingo , Ohnishi Kouji , Dobashi Kazuhito , Watanabe Jun-ichi , Miyata Takashi , Nakada Yoshikazu 
Published: March 2014

Abstract
We report on the results of CCD imaging of the radiant points of Leonids with the 105 cm Kiso Schmidt telescope during its storm in 2001. The center coordinates of the observed field were $\alpha(\mathrm{J}2000.0) = {10{}^{\mathrm {h}}17{}^{\mathrm {m}}02\rlap {.}{}^{\mathrm {s}}4}$ and $\delta(\mathrm{J}2000.0) = + {21{}^{\mathrm {\circ }}37{}^{\mathrm {\prime }}48\rlap {.}{}^{\mathrm {\prime \prime }}0}$, corresponding to the center position between the two radiant points originating from dust trails created by the 1699 and 1866 returns of the Comet 55P/Tempel–Tuttle (McNaught, Asher 2001; WGN, 29, 156). Six CCD images having a field of view of ${51\rlap {.}{}^{\mathrm {\prime }}2} \times {51\rlap {.}{}^{\mathrm {\prime }}2}$ were obtained successively from 16h 58 m to 18h 28 m on November 18 (UT) in order to cover the two expected peaks of activity of the distinct radiant points. A limiting surface brightness of $25.93 \,\mathrm{mag} \,\mathrm{arcsec}^{-2}$, i.e., the $1\,\sigma$ noise level of the sky background, was achieved in each image. As a result, we detected only one faint Leonid meteor which most likely originated from a dust trail created by the 1866 return. The integrated total magnitude of the meteor is $m_{V}=18.34\pm 0.34 \,\mathrm{mag}$ on the image. Assuming a duration time of 0.1–1 s, we estimate the magnitude at the maximum luminosity of this meteor to be $9.70\pm 1.59 \,\mathrm{mag}$. This corresponds to a photometric mass of $(2.65^{+13.5}_{-2.22})\times 10^{-10} \,\mathrm{kg}$, which makes this meteor one of the faintest and smallest Leonids detected so far.