bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproducibility of Non-X-Ray Background for the X-Ray Imaging Spectrometer aboard Suzaku
Authors: Tawa Noriaki , Hayashida Kiyoshi , Nagai Masaaki , Nakamoto Hajime , Tsunemi Hiroshi , Yamaguchi Hiroya , Ishisaki Yoshitaka , Miller Eric D. , Mizuno Tsunefumi , Dotani Tadayasu , Ozaki Masanobu , Katayama Haruyoshi 
Published: March 2014

Abstract
One of the advantages of the X-ray Imaging Spectrometer (XIS) system aboard Suzaku is its low and stable non-X-ray background (NXB). In order to make the best use of this advantage, modeling the NXB spectra with high accuracy is important to subtract them from the spectra of on-source observations. We are constructing an NXB database by collecting XIS events when the the dark Earth covers the XIS FOV. The total exposure time of the NXB data is presently about 785ks for each XIS. It is found that the count rate of the NXB anti-correlates with the cut-off-rigidity and correlates with the count rate of the PIN upper discriminator (PIN-UD) in the Hard X-ray Detector aboard Suzaku. We thus model the NXB spectrum for a given on-source observation by employing either of these parameters, and obtain a better reproducibility of the NXB for the model with PIN-UD than that with the cut-off-rigidity. The reproducibility of the NXB model with PIN-UD is 4.55-5.63% for each XIS NXB in the 1-7keV band and 2.79-4.36% for each XIS NXB in the 5-12keV band for each 5ks exposure of the NXB data. This NXB reproducibility is much smaller than the spatial fluctuation of the cosmic X-ray background in the 1-7keV band, and is almost comparable to that in the 5-12keV band.
Discovery of Extended X-Ray Emission from an Unidentified TeV Source, HESS J1614$-$518, Using the Suzaku Satellite
Authors: Matsumoto Hironori , Uchiyama Hideki , Sawada Makoto , Tsuru Takeshi G. , Koyama Katsuji , Katagiri Hideaki , Yamazaki Ryo , Bamba Aya , Kohri Kazunori , Mori Koji , Uchiyama Yasunobu 
Published: March 2014

Abstract
We report Suzaku results concerning HESS J1614$-$518, which is the brightest extended TeV gamma-ray source discovered in the Galactic plane survey conducted using the H.E.S.S. telescope. We discovered three X-ray objects in the field of view of the X-ray Imaging Spectrometer, which were designated as Suzaku J1614$-$5141 (src A), Suzaku J1614$-$5152 (src B), and Suzaku J1614$-$5148 (src C). Src A is an extended source located at the peak position of HESS J1614$-$518, and is therefore a plausible counterpart to HESS J1614$-$518. The X-ray flux in the 2-10keV band is 5$\times 10^{-13}$ergs$^{-1}$cm$^{-2}$, which is an order of magnitude smaller than the TeV flux. The photon index is 1.7, which is smaller than the canonical value of synchrotron emissions from high-energy electrons found in some supernova remnants. These findings present a challenge to models in which the origin of TeV emission is inverse Compton scattering of the cosmic microwave background by accelerated electrons that emit X-rays via synchrotron emission. Src B is located at a relatively dim region in the TeV band image; however, its hydrogen column density is the same as that of src A. Therefore, src B may also be physically related to HESS J1614$-$518. Src C is a foreground late-type B star. We also discovered soft extended X-ray emission near HESS J1614$-$518.
Detailed Hard X-Ray Measurements of Nuclear Emission from the Seyfert2 Galaxy NGC4388 with Suzaku
Authors: Shirai Hirohisa , Fukazawa Yasushi , Sasada Mahito , Ohno Masanori , Yonetoku Daisuke , Yokota Satoshi , Fujimoto Ryuichi , Murakami Toshio , Terashima Yuichi , Awaki Hisamitsu , Ikeda Shinya , Ozawa Midori , Tsuru Takeshi G. 
Published: March 2014

Abstract
We report on a Suzaku observation of the nearby Seyfert2 galaxy NGC4388. The overall spectrum is well described by the combination of strongly absorbed power-law plus thin thermal plasma emission, as well as previous observations. Thanks to well-calibrated instruments and a low background level, Suzaku measured the broad-band X-ray spectra more precisely than ever, and enabled us to probe the physical structure of the nuclear region. In addition, a time variability having a factor of 1.5 with a half-day time scale was found up to above 10keV. The center energy and the K$\beta$/K$\alpha$ ratio of the narrow Fe-K line, together with less time variability, indicate that the fluorescent material is far from the black hole. A spectral hump around the 30-40keV band, together with a Compton shoulder of the Fe-K line, requires a significant contribution of the reflection component. This is also consistent with a smaller amplitude of time variability in a higher energy band. A large contribution of the reflection component was not observed by the CGRO/OSSE and BeppoSAX, suggesting that NGC4388 had been in a higher flux state, and that Suzaku observed its light echo. A He-like Fe-K$\alpha$ absorption line was also detected, indicating the existence of highly ionized plasma.
Wide-Band Spectroscopy of the Compton Thick Seyfert2 Galaxy Markarian 3 with Suzaku
Authors: Awaki Hisamitsu , Anabuki Naohisa , Fukazawa Yasushi , Gallo Luigi C. , Ikeda Shinya , Isobe Naoki , Itoh Takeshi , Kunieda Hideyo , Makishima Kazuo , Markowitz Alex , Miniutti Giovanni , Mizuno Tsunefumi , Okajima Takashi , Ptak Andrew , Reeves James N. , Takahashi Tadayuki , Terashima Yuichi , Yaqoob Tahir 
Published: March 2014

Abstract
We obtained a wide-band spectrum of the Compton-thick Seyfert2 galaxy Mkn3 with Suzaku. The observed spectrum was clearly resolved into weak, soft power-law emission, a heavily absorbed power-law component, cold reflection, and many emission lines. The heavily absorbed component, absorbed by gas with a column density of 1.1$\times$10$^{24}$cm$^{-2}$, has an intrinsic 2-10keV luminosity of $\sim$1.6$\times$10$^{43}$ergs$^{-1}$, and is considered to be direct emission from the Mkn3 nucleus. The reflection component was interpreted as being the reflection of direct light off a cold, thick material; the reflection fraction, $R$, was 1.36$\pm$0.20. The cold material is inferred to be located $&gt;$ 1 pc from the central black hole of Mkn3, due to the low ionization parameter of iron ($\xi &lt;$ 1ergcms$^{-1}$) and the narrow iron line width ($\sigma$$&lt;$ 22eV). The weak, soft power-law emission is considered to be scattered light by ionized gas with a scattering fraction of 0.9$\pm$0.2%. The existence of many highly ionized lines in the observed spectrum indicates that the ionized gas has a broad ionized structure, with $\xi =$ 10-1000 ergcms$^{-1}$. This high-quality spectrum obtained by Suzaku can be considered to be a template for studies of Seyfert2 galaxies.
High Metallicity of the X-Ray Gas Up to the Virial Radius of a Binary Cluster of Galaxies: Evidence of Galactic Superwinds at High-Redshift
Authors: Fujita Yutaka , Tawa Noriaki , Hayashida Kiyoshi , Takizawa Motokazu , Matsumoto Hironori , Okabe Nobuhiro , Reiprich Thomas. H. 
Published: March 2014

Abstract
We present an analysis of a Suzaku observation of the link region between the galaxy clusters A 399 and A 401. We obtained the metallicity of the intracluster medium (ICM) up to the cluster virial radii for the first time. We determined the metallicity where the virial radii of the two clusters cross each other ($\sim 2$ Mpc away from their centers) and found that it is comparable to that in their inner regions ($\sim 0.2\: Z_\odot$). It is unlikely that the uniformity of metallicity up to the virial radii is due to mixing caused by a cluster collision. Since the ram-pressure is too small to strip the interstellar medium of galaxies around the virial radius of a cluster, the fairly high metallicity that we found there indicates that the metals in the ICM are not transported from member galaxies by ram-pressure stripping. Instead, the uniformity suggests that the proto-cluster region was extensively polluted with metals by extremely powerful outflows (superwinds) from galaxies before the clusters formed. We also searched for the oxygen emission from the warm-hot intergalactic medium in that region and obtained a strict upper limit of the hydrogen density ($n_{\rm H}&lt;4.1\times 10^{-5}$ cm$^{-3}$).
Albedo, Size, and Surface Characteristics of Hayabusa-2 Sample-Return Target 162173 1999 JU3 from AKARI and Subaru Observations
Authors: Hasegawa Sunao , MüLler Thomas G. , Kawakami Kyoko , Kasuga Toshihiro , Wada Takehiko , Ita Yoshifusa , Takato Naruhisa , Terada Hiroshi , Fujiyoshi Takuya , Abe Masanao 
Published: March 2014

Abstract
Mid-infrared observations of the Apollo-type asteroid 162173 1999 JU3 were performed in 2007 May during its close Earth approach with the AKARI space telescope and in 2007 August with the Subaru telescope. A thermophysical model analysis of the obtained data resulted in a radiometric diameter of 0.92$\pm$0.12km and a visual geometric albedo of 0.063$^{+0.020}_{-0.015}$. The geometric albedo is typical for C-type asteroids. The solutions for the thermal inertia of 1999 JU3's surface material were not as clear as for the asteroid 25143 Itokawa due to less-favorable observing conditions. But the most likely solutions are connected to high thermal inertia values, indicating that the surface is predominantly covered by boulders and bare rocks, while areas with thick dust regolith are less common.
AKARI/FIS Mapping of the ISM-Wind Bow Shock around $\alpha $ Orionis
Authors: Ueta Toshiya , Izumiura Hideyuki , Yamamura Issei , Nakada Yoshikazu , Matsuura Mikako , Ita Yoshifusa , TanabÉ Toshihiko , Fukushi Hinako , Matsunaga Noriyuki , Mito Hiroyuki 
Published: March 2014

Abstract
We present $10$$\times$50scan maps around an M supergiant $\alpha $ Ori at 65, 90, 140, and 160$\mu$m obtained with the AKARI Infrared Astronomy Satellite. Higher spatial resolution data with the exact analytic solution permit us to fit the de-projected shape of the stellar-wind bow shock around $\alpha $ Ori to have a stand-off distance of $4\farcm8$, position angle of 55$^{\circ}$ and inclination angle of 56$^{\circ}$. The shape of the bow shock suggests that the velocity of $\alpha $ Ori with respect to the local medium is $v_* = 40n_{\rm H}^{-1/2}$, where $n_{\rm H}$ is the hydrogen nucleus density at $\alpha $ Ori. We found that the local medium is of $n_{\rm H} =$ 1.5 to 1.9cm$^{-3}\rule[3mm]{0mm}{0mm}$ and the velocity of the local flow is at 11kms$^{-1}$ by using the most recent astrometric solutions for $\alpha $ Ori under the assumption that the medium local to $\alpha $ Ori is moving away from the Orion OB 1 association. AKARI images may also reveal a vortex ring due to instabilities on the surface of the bow shock, as demonstrated by numerical models. This research exemplifies the potential of AKARI All-Sky data as well as follow-up observations with Herschel Space Telescope and Stratospheric Observatory for Infrared Astronomy for this avenue of research in revealing the nature of the interaction between the stellar wind and the interstellar medium.
Supernova Remnants in the AKARI IRC Survey of the Large Magellanic Cloud
Authors: Seok Ji Yeon , Koo Bon-Chul , Onaka Takashi , Ita Yoshifusa , Lee Ho-Gyu , Lee Jae-Joon , Moon Dae-Sik , Sakon Itsuki , Kaneda Hidehiro , Lee Hyung Mok , Lee Myung Gyoon , Kim Sung Eun 
Published: March 2014

Abstract
We present a near- to mid-infared study of supernova remnants (SNRs) using the AKARI IRC Survey of the Large Magellanic Cloud (LMC). The LMC survey observed about a 10 square degree area of the LMC in five bands centered at 3, 7, 11, 15, and 24$\mu$m using the Infrared Camera (IRC) aboard AKARI. The number of SNRs in the survey area is 21, which is about a half of the known LMC SNRs. We systematically examined AKARI images and identified eight SNRs with distinguishable infrared emission. All of them were detected at $\gtrsim$10$\mu$m and some at 3 and 7$\mu$m, too. We present their AKARI images and fluxes. In the 11$/$15$\mu$m versus 15$/$24$\mu$m color-color diagram, the SNRs appear to be aligned along a modified blackbody curve, representing thermal emission from dust at temperatures of between 90 and 190K. There is a good correlation between the 24$\mu$m and X-ray fluxes of the SNRs. It was also found that there is a good correlation between the 24$\mu$m and radio fluxes even if there is no direct physical connection between them. We considered the origin of the detected mid-infrared emission in individual SNRs. We conclude that the mid-infrared emissions in five SNRs that show morphologies similar to the X-rays are dominated by thermal emission from hot dust heated by X-ray emitting plasma. Their 15$/$24$\mu$m color temperatures are generally higher than the Spitzer 24$/$70$\mu$m color temperatures, which suggests that a single-temperature dust model cannot describe the full spectral energy distribution (SED) of the SNRs. It also implies that our understanding of the full SED is essential for estimating the dust destruction rate of grains by SNR shocks.
Discovery of the Inner Ring around PSR B1509$-$58
Authors: Yatsu Yoichi , Kawai Nobuyuki , Shibata Shinpei , Brinkmann Wolfgang 
Published: March 2014

Abstract
A Chandra study of a pulsar wind nebula around the young energetic pulsar PSR B1509$-$58 is presented. A high-resolution X-ray image with a total exposure time of 190 ks reveals a ringlike feature $10^{\prime\prime}$ apart from the pulsar. This feature is analogous to the inner ring seen in the Crab nebula, and thus may correspond to wind termination shock. The shock radius enables us to constrain the wind magnetization, $\sigma$$\geq$ 0.01, which is one order of magnitude larger than that of the Crab nebula. In the vicinity of the pulsar, the south jet appears to be as broad as the diameter of the inner ring at its beginning, in contrast to the narrow jet of the Crab. This morphology of the broad jet is consistent with a recently proposed theoretical model in which magnetic hoop stress diverts and squeezes the postshock equatorial flow toward the poloidal direction, generating a jet.
Global Disk Oscillations in Binary Be Stars
Authors: Oktariani Finny , Okazaki Atsuo T. 
Published: March 2014

Abstract
We consider the effects of the tidal interaction with the companion, via orbital separation and the binary mass ratio, on the global one-armed oscillation modes in disks around binary Be stars. Our model takes into account a three-dimensional effect that contributes to mode confinement, which was recently found by Ogilvie (2008). We find that the one-armed oscillations are well confined in systems with disks larger than a few tens of stellar radii. In such systems, the oscillation period depends little on the binary parameters. On the other hand, in systems with smaller disks, where mode confinement is incomplete, the oscillation period increases with increasing orbital separation and/or decreasing binary mass ratio. The eigenmode is insensitive to the spectral type of the central star. Our results suggest that the dependence of the V$/$R oscillation period on the orbital separation and binary mass ratio should be observed only in short-period binary systems, and that, for systems with a similar orbital period, those with higher mass ratios will show shorter V$/$R variations.
Kinematic and Excitation Structure of the NGC 1068 Narrow-Line Region
Authors: Ozaki Shinobu 
Published: March 2014

Abstract
We investigated the kinematic and excitation structure of the NGC 1068 narrow-line region (NLR). We obtained profiles of several emission lines ([O iii]$\lambda$5007, H$\beta$, [O i]$\lambda$6300, and [Fe vii]$\lambda$6087) at high-velocity resolution ($R$$\sim$ 7500–11000), and confirmed that they showed different profiles. These profiles are useful for understanding the NLR structure, since they cover a wide ionization-potential range. By comparing the results with a photoionization model, we found that: (1) blueshifted components at the center are very dense, (2) those in the northeast region have slightly lower densities than those in the center, and (3) the ionization parameters of the blueshifted components increase with increasing velocity with respect to the systemic velocity. We investigated the NLR structure in NGC 1068 based on these results. We show that both the observed velocity dependence of the ionization parameter and the gradually increasing velocity field can be reproduced by varying the ionizing continuum attenuation, assuming a hollowed biconical geometry and varying the column densities of outflowing clouds.
Spectropolarimetry with the Hida Domeless Solar Telescope
Authors: Hanaoka Yoichiro 
Published: March 2014

Abstract
We developed a spectropolarimetry system with a ferroelectric liquid crystal polarization modulator for the 60-cm Domeless Solar Telescope of Hida Observatory. The telescope is equipped with two oblique-reflection mirrors, that alter the incident polarization before it reaches the polarimeter. Furthermore, it is impossible to calibrate the polarimeter using unpolarized light because of the instrumental polarization. Here, we develop a procedure to obtain the parameters of both the instrumental polarization and for the calibration of the polarimeter from the same calibration data sets. We apply the new procedure to carry out high-sensitivity spectropolarimetry. It is now possible to measure the polarizations of various photospheric and chromospheric lines with the Domeless Solar Telescope.
Evidence from the Extreme-Ultraviolet Imaging Spectrometer for Axial Filament Rotation before a Large Flare
Authors: Williams David R. , Harra Louise K. , Brooks David H. , Imada Shinsuke , Hansteen Viggo H. 
Published: March 2014

Abstract
In this article, we present observations made with the Extreme-ultraviolet Imaging Spectrometer on-board the Hinode solar satellite, of an active region filament in the HeII emission line at 256.32 $Å$. The host active region AR 10930 produces an X-class flare during these observations. We measure Doppler shifts with apparent velocities of up to 20 kms$^{-1}$, which are antisymmetric about the filament length and occur several minutes before the flare’s impulsive phase. This is indicative of a rotation of the filament, which is in turn consistent with expansion of a twisted flux rope due to the MHD helical kink instability. This is the first time that such an observation has been possible in this transition-region line, and we note that the signature observed occurs before the first indications of pre-flare activity in the GOES solar soft X-ray flux, suggesting that the filament begins to destabilise in tandem with a reorganization of the local magnetic field. We suggest that this expansion is triggered by the decrease of magnetic tension around, and/or total pressure above, the filament.
AKARI Far-Infrared Spectroscopic Observations of the Galactic Center Region
Authors: Yasuda Akiko , Kaneda Hidehiro , Nakagawa Takao , Okada Yoko , Kawada Mitsunobu , Murakami Noriko , Takahashi Hidenori , Ootsubo Takafumi 
Published: March 2014

Abstract
We have observed the Quintuplet- and Arches-cluster regions with the Fourier Transform Spectrometer (FTS) of the Far-Infrared Surveyor (FIS) aboard AKARI to investigate the physical conditions of interstellar matter around the clusters. The FIS-FTS mapping data reveal differences in the spatial distribution among the far-infrared [O iii], [N ii], and [C ii] line emissions near the Arches cluster; the emission of an ionic line with a higher ionization potential is distributed closer to the Arches cluster. This clearly indicates that UV photons from the Arches cluster are ionizing the surface of nearby molecular clouds, and penetrating deeper to dissociate the cloud. We have estimated the effective temperature of the Arches cluster to be about 34000 K from the ratio of the [O iii]$/$[N ii] lines.
SDSS J080434.20$+$510349.2: Eclipsing WZ Sge-Type Dwarf Nova with Multiple Rebrightenings
Authors: Kato Taichi , Pavlenko Elena P. , Maehara Hiroyuki , Nakajima Kazuhiro , Andreev Maksim , Shugarov Sergei Yu. , De Ponthière Pierre , Brady Steve , Klingenberg Geir , Shears Jeremy , Imada Akira , Yanagisawa Kenshi 
Published: March 2014

Abstract
We observed the 2006 superoutburst of SDSS J080434.20$+$510349.2 during its plateau phase, rebrightening phase, and post-superoutburst final decline. We found that this object is a grazing eclipsing system with a period of 0.0590048(2)d. Well-defined eclipses were only observed during the late stage of the superoutburst plateau and the depth decreased during the subsequent stages. We determined the superhump period during the superoutburst plateau to be 0.059539(11)d, giving a fractional superhump excess of 0.90(2)%. During the rebrightening and post-superoutburst phases, persisting superhumps have periods longer than those of superhumps during the plateau phase: 0.059632(6)d during the rebrightening phase and 0.05969(4)d during the final fading. This phenomenon is very well in line with the previously known long-period “late superhumps” in GW Lib, V455 And, and WZ Sge. The amplitudes of orbital humps between different states of rebrightenings suggest that these humps do not arise from the classical hot spot, but are more likely to be a result of projection effect in a high-inclination system. There was no clear evidence for an enhanced hot spot during the rebrightening phase. We also studied previously reported “mini-outbursts” in the quiescent state, and found evidence that superhumps were transiently excited during these mini-outbursts. The presence of grazing eclipses and distinct multiple rebrightenings in SDSS J080434.20$+$510349.2 would provide a unique opportunity for understanding the mechanism of rebrightenings in WZ Sge-type dwarf novae.
Observational Appearance of Luminous Relativistic Movers
Authors: Fukue Jun 
Published: March 2014

Abstract
We examine the observational appearance of optically thick luminous gaseous objects that move or rotate at a relativistic speed. In relativistic objects traveling at about the speed of light, Doppler and aberration effects influence their observational appearance. In gaseous objects with a hotter interior, furthermore, there exists a usual limb-darkening effect, which has a direction-dependency, and is therefore affected by the relativistic aberration. In addition, the emitted radiation suffers from a relativistic Doppler boost. Hence, the apparent photosphere of relativistic gaseous objects depends on their velocity and direction as well as the temperature distribution. We have derived the optical depth of the apparent photosphere of such relativistic movers under the plane-parallel approximation, and calculated several typical cases. When the velocity is almost parallel to the line of sight, the relativistic effect on the optical depth becomes important; otherwise, the limb-darkening effect dominates. In the case of a rotating sphere, except for some small fraction in the equatorial direction, the optical depth of the apparent photosphere becomes small due to the relativistic aberration. In the case of a geometrically thin disk, the optical depth becomes large in the left approaching part, whereas it becomes small in the right receding part. In the case of a geometrically thick disk, the projection effect becomes important, and the optical depth is large at the far side, while it is small at the near side. We have also examined light curves of luminous orbiters around a black hole and luminosities and spectra of accretion disks under special relativity, as applications. The light curve of the relativistic orbiter does deviate from a sinusoidal pattern due to the transverse Doppler effect. The pole-on luminosity of accretion disks is enhanced by the limb-dakening effect and reduced by the relativistic one, while the luminosity observed from the inclined direction is reduced by the limb-darkening effect.