bluuebunny/crossref_metadata_2025_split huggingface dataset:
CCD Photometric Study of the Contact Binary TX Cnc in the Young Open Cluster NGC 2632
Authors: Liu Liang , Qian Sheng-Bang , Boonrucksar Soonthornthum , Zhu Li-Ying , He Jia-Jia , Yuan J.-Z. 
Published: March 2014

Abstract
TX Cnc is a member of the young open cluster NGC2632. In the present paper, four CCD epochs of light minimum and a complete $V$ light curve of TX Cnc are presented. A period investigation based on all available photoelectric or CCD data showed that it is superimposed on a long-term increase ($dP/dt=+3.97\times{10^{-8}}$d yr$^{-1}$), and weak evidence suggests that it includes a small-amplitude period oscillation ($A_3=0\rlap{.}^{\rm d} 0028$; $T_3=26.6$yr). The light curves in the $V$ band obtained in 2004 were analyzed with the 2003 version of the W-D code. It was shown that TX Cnc is an overcontact binary system with a degree of contact factor $f=24.8\% (\pm0.9\%)$. The absolute parameters of the system were calculated: $M_1=1.319\pm0.007M_{\odot}, M_2=0.600\pm0.01M_{\odot}$; $R_1=1.28\pm0.19R_{\odot}, R_2=0.91\pm0.13R_{\odot}$. TX Cnc may be on the TRO-controlled stage of the evolutionary scheme proposed by Qian (2001a, b, 2003a), and may contain an invisible tertiary component ($m_3\approx0.097M_{\odot}$). If this is true, the tertiary component has played an important role in the formation and evolution of TX Cnc by removing angular momentum from the central system (Pribulla & Rucinski 2006). In this way the contact binary configuration can be formed in the shortlife time of a young open cluster via AML.
The Core Radius of a Star Cluster Containing a Massive Black Hole
Authors: Heggie Douglas C. , Hut Piet , Mineshige Shin , Makino Junichiro , Baumgardt Holger 
Published: March 2014

Abstract
We present a theoretical framework which establishes how the core radius of a star cluster varies with the mass of an assumed central black hole. Our result is that $r_{\rm c}/r_{\rm h}\propto (M_{\rm bh}/M)^{3/4}$ when the system is well relaxed. The theory compares favourably with a number of simulations of this problem, which extend to black hole masses of order 10% of the cluster mass. Though strictly limited as yet to clusters with stars of equal mass, our conclusion strengthens the view that clusters with large core radii are the most promising candidates in which to find a massive black hole.
First Determination of the Actinide Thorium Abundance for a Red Giant of the Ursa Minor Dwarf Galaxy
Authors: Aoki Wako , Honda Satoshi , Sadakane Kozo , Arimoto Nobuo 
Published: March 2014

Abstract
The thorium abundance of the red giant COS 82 in the Ursa Minor dwarf spheroidal galaxy was determined based on the high-resolution spectrum. This is the first detection of actinides in an extragalactic object. A detailed abundance pattern was determined for 12 other neutron-capture elements from atomic number 39 to 68. These elements are significantly over-abundant with respect to other metals, like Fe ($\gt$ 1 dex), and their abundance pattern agrees well with those of the r-process-enhanced, very metal-poor stars known in the galactic halo, while the metallicity of this object ([Fe$/$H] $\sim -$1.5) is much higher than these field stars ([Fe$/$H] $\sim-3.0$). The results indicate that the mechanism and the astrophysical site that are responsible for neutron-capture elements in COS 82 are similar to that for field r-process-enhanced stars, while the condition of low-mass star formation is quite different. An estimate of the age of this object based on the Th abundance ratio is discussed.
Chandra Detections of Diffuse X-Ray Emission from Globular Clusters
Authors: Okada Yuu , Kokubun Motohide , Yuasa Takayuki , Makishima Kazuo 
Published: March 2014

Abstract
Using Chandra, extended X-ray emission was detected from the direction of 6 globular clusters: 47 Tucanae, NGC 6752, M 5, $\omega$ Centauri, M 80, and NGC 6266. These X-ray sources, extending to a few arcmin, are located $1'-6'$ away from the cluster centers, and some are found in the direction of cluster motion through the Galactic halo. All of these sources are concluded to be diffuse, rather than an assembly of faint discrete X-ray sources. Those in 47 Tuc and NGC 6752 have similar spectra, described by a power law with a photon index of $\sim 2$, or a thin-thermal model with a temperature of $\sim 3 \!-\!4$ keV. Furthermore, they both have 843 MHz radio counterparts. The diffuse emission from $\omega$ Cen exhibits a $\sim 1.0$ keV thermal spectrum, while that from M 5 shows an even softer ($\sim$ 0.05 keV) spectrum. While the diffuse source in $\omega$ Cen could be a background contaminant, the others are likely to be physically associated with the globular clusters. Then, the absorption-corrected 0.5–4.5 keV luminosity of the sources in 47 Tuc and NGC 6752 becomes $(3\!-\!6)\times 10^{32}$ erg s$^{-1}$. These results are discussed in the context of shocks produced by the cluster motion through the Galactic halo, and the associated gas heating and particle acceleration.
Measurement of the Rossiter–McLaughlin Effect in the Transiting Exoplanetary System TrES-1
Authors: Narita Norio , Enya Keigo , Sato Bun’ei , Ohta Yasuhiro , Winn Joshua N. , Suto Yasushi , Taruya Atsushi , Turner Edwin L. , Aoki Wako , Tamura Motohide , Yamada Toru , Yoshii Yuzuru 
Published: March 2014

Abstract
We report a measurement of the Rossiter–McLaughlin effect in the transiting extrasolar planetary system TrES-1, via simultaneous spectroscopic and photometric observations with the Subaru and MAGNUM telescopes. By modeling the radial velocity anomaly that was observed during a transit, we determine the sky-projected angle between the stellar spin axis and the planetary orbital axis to be $\lambda = 30^{\circ}\pm 21^{\circ}$. This is the third case for which $\lambda$ has been measured in a transiting exoplanetary system, and the first demonstration that such measurements are possible for relatively faint host stars ($V \sim$ 12, as compared to $V \sim$ 8 for the other systems). We also derive a time of mid-transit, constraints on the eccentricity of the TrES-1b orbit ($e =$ 0.048$\pm$0.025), and upper limits on the mass of the Trojan companions ($\lesssim$ 14 $M_{\oplus}$) at the 3$\sigma$ level.
Dramatic Spectral and Photometric Changes of Pleione (28 Tau) between 2005 November and 2007 April
Authors: Tanaka Ken’ichi , Sadakane Kozo , Narusawa Shin-ya , Naito Hiroyuki , Kambe Eiji , Katahira Jun-ichi , Hirata Ryuko 
Published: March 2014

Abstract
Recent photometric and spectroscopic observations of Pleione are reported. Pleione showed brightness declines in both the $B$ and $V$ bands by $\sim$ 0$\rlap {.}{^{\rm m}}$25 between 2006 January and 2007 March. Significant decreases in the strengths and widths of the long-lived emission components in H$\alpha$ and H$\beta$ were observed during this period, while additional outer double-emission components appeared in these lines. Many metallic shell lines strengthened during the observation period, being accompanied by central quasi-emission components. We interpret these spectral changes in terms of a double disk: the progressive decline of a misaligned old disk in due course of precession and the formation and growth of a new disk in the star’s equatorial plane.
Distance to Orion KL Measured with VERA
Authors: Hirota Tomoya , Bushimata Takeshi , Choi Yoon Kyung , Honma Mareki , Imai Hiroshi , Iwadate Kenzaburo , Jike Takaaki , Kameno Seiji , Kameya Osamu , Kamohara Ryuichi , Kan-ya Yukitoshi , Kawaguchi Noriyuki , Kijima Masachika , Kim Mi Kyoung , Kobayashi Hideyuki , Kuji Seisuke , Kurayama Tomoharu , Manabe Seiji , Maruyama Kenta , Matsui Makoto , Matsumoto Naoko , Miyaji Takeshi , Nagayama Takumi , Nakagawa Akiharu , Nakamura Kayoko , Oh Chung Sik , Omodaka Toshihiro , Oyama Tomoaki , Sakai Satoshi , Sasao Tetsuo , Sato Katsuhisa , Sato Mayumi , Shibata Katsunori M. , Shintani Motonobu , Tamura Yoshiaki , Tsushima Miyuki , Yamashita Kazuyoshi 
Published: March 2014

Abstract
We present the initial results of multiepoch VLBI observations of 22 GHz H$_{2}$O masers in the Orion KL region with VERA (VLBI Exploration of Radio Astrometry). With the VERA dual-beam receiving system, we carried out phase-referencing VLBI astrometry, and successfully detected the annual parallax of Orion KL to be 2.29$\;\pm\;$0.10 mas, corresponding to a distance of 437$\;\pm\;$19 pc from the Sun. The distance to Orion KL was determined for the first time with the trigonometric parallax method in these observations. Although this value is consistent with that previously reported, 480$\;\pm\;$80 pc, which was estimated from a statistical parallax method using the proper motions and radial velocities of the H$_{2}$O maser features, our new results provide a much more accurate value with an uncertainty of only 4%. In addition to the annual parallax, we detected an absolute proper motion of the maser feature, suggesting an outflow motion powered by the radio source I along with the systematic motion of source I itself.
Self-Gravitational Magnetohydrodynamics with Adaptive Mesh Refinement for Protostellar Collapse
Authors: Matsumoto Tomoaki 
Published: March 2014

Abstract
A new numerical code, called SFUMATO, for solving self-gravitational magnetohydrodynamics (MHD) problems using adaptive mesh refinement (AMR) is presented. A block-structured grid is adopted as the grid of the AMR hierarchy. The total variation diminishing (TVD) cell-centered scheme is adopted as the MHD solver, with hyperbolic cleaning of the divergence error of the magnetic field also implemented. The MHD solver exhibits a second-order accuracy in convergence tests of linearized MHD waves. The self-gravity is solved using a multigrid method composed of (1) a full multigrid (FMG)-cycle on the AMR hierarchical grids, (2) a V-cycle on these grids, and (3) an FMG-cycle on the base grid. The multigrid method exhibits spatial second-order accuracy, fast convergence, and scalability. The numerical fluxes are conserved by using a refluxing procedure in both the MHD solver and the multigrid method. Several tests are performed and the results indicate that the solutions are consistent with previously published results.
Radiative Column and Light Curve of X-Ray Binary Pulsars
Authors: Karino Shigeyuki 
Published: March 2014

Abstract
We examine the published light curves (LCs) of 117 X-ray binary pulsars, while focusing on the dependence of their light curves on the observed energy bands. It is found that the energy dependence of the LCs appears only when the X-ray luminosity is larger than $\sim\;$5 $\times {10^{36}}\;$ergs$^{-1}$. Assuming that the behavior of light curve is related to the radiative accretion column on the neutron-star surface, this energy threshold can be considered as observational proof of the accretion column formation proposed by Basko and Sunyaev. Once we can grasp the existence of a radiative column, we can also obtain several useful pieces of information about the neutron-star properties. As an instance, we performed a statistical analysis of the orientation angle of the magnetic axis, and we found that the inclination angle of the magnetic axis should be small in order to explain the observed statistics.
Observations of B335 in the Millimeter Continuum and the 226 GHz H$_2$CO Line
Authors: Choi Minho 
Published: March 2014

Abstract
The protostar B335 was observed in the 1.3 mm continuum and in the H$_2$CO 3$_{12} \rightarrow$ 2$_{11}$ line with an angular resolution of about 8$^{\prime\prime}$. The mass of the inner envelope, detected by the dust continuum emission, is about 0.02$M_\odot$. The H$_2$CO spectrum at the protostellar position shows a blue-skewed double-peak profile, suggesting that the kinematics of the inner envelope is dominated by infall motion. When the blueshifted and the redshifted peaks were imaged separately, however, a small east–west displacement was found between the maximum positions. This displacement suggests that some part of the H$_2$CO emission might come from the outflowing gas. A combined effect of the infalling envelope and the outflow on the radiative transfer is discussed. This effect can make the line profile asymmetry severer than what is expected from infall-only models.
Missing Dwarf Problem in Galaxy Clusters
Authors: Kase Hiroyuki , Makino Junichiro , Funato Yoko 
Published: March 2014

Abstract
We investigated the formation and evolution of CDM subhalos in galaxy-sized and cluster-sized halos by means of $N$-body simulations. Our aim was to make clear what the “dwarf galaxy problem” is. It has been argued that the number of subhalos in simulated galaxy-sized halos is too large compared with the observed number of dwarfs in the local group, while that in cluster-sized halos is consistent with the observed number of galaxies in clusters, such as the Virgo cluster. We simulated nine halos with several different mass resolutions and physical scales. We found that the dependence of the cumulative number of subhalos, $N_c$, on their maximum circular velocity, $V_c$, is given by $N_c\propto V_c^{-3}$, down to the reliability limit, independent of the mass of the main halo. This implies that simulations for cluster-sized halos give too many halos with $V_c \sim$140 km s$^{-1}$ or less. Previous comparisons of cluster-sized halos gave a much smaller number of subhalos in this regime, simply because of their limited resolution. Our result implies that any theory that attempts to resolve the missing dwarf problem should also explain the discrepancy of the simulation and observation in cluster-sized halos.
Abundances of Volatile Elements in Post-AGB Candidates
Authors: Takeda Yoichi , Taguchi Hikaru , Yoshioka Kazuo , Hashimoto Osamu , Aikawa Toshiki , Kawanomoto Satoshi 
Published: March 2014

Abstract
A detailed non-LTE study on the abundances of C, N, O, S, and Zn was carried out for five F–G supergiants of suspected post-AGB candidates with IR excesses (HD 112374, HD 148743, HD 161796, HD 163506, and HD 187203), since these volatile elements can provide the key to inferring the original metallicity as well as an evolution-induced change due to mixing, given that they are free from depletion caused by dust–gas separation. The extent of separation-induced depletion in Fe, estimated by comparing with Zn, turned out to be rather moderate ($\lesssim$ several tenths dex). The characteristics of the C, N, and O abundances do not appear to be very different from the case of the first dredge-up in normal supergiants (decreased C and enriched N due to the first dredge-up); thus, the specific anomaly related to an advanced post-AGB stage so far reported (such as elevated C and O) could not be clearly confirmed.
A Bright Transient X-Ray Source Near the Galactic Center Found in Archival Ginga Data from 1987
Authors: Yamauchi Shigeo , Nakagawa Yoshio , Sudoh Keisuke , Kitamoto Shunji 
Published: March 2014

Abstract
A bright transient X-ray source was detected in the direction of the galactic center with Ginga in 1987 March. A sky position was determined from both data obtained with the All Sky Monitor (ASM) and cross-scan data obtained with the Large Area proportional Counters (LAC). Based on the sky position derived from both the ASM and the LAC data, this source was designated as GS 1741$-$288. At the beginning of the Ginga observations, GS 1741$-$288 was in the active state: its energy flux in the 2–10 keV energy band was $\sim$10$^{-8}$ergs$^{-1}$cm$^{-2}$. The ASM light curve showed that the intensity gradually decayed with an e-folding time of $190\pm9$d. No remarkable feature, such as periodic or quasi-periodic oscillations was found. The spectral and temporal properties suggest that GS 1741$-$288 is likely to be a low-mass X-ray binary system containing a weakly magnetized neutron star. Possible identification of the source is also discussed.
Subaru Near-Infrared Multicolor Images of Class II Young Stellar Object, RNO 91
Authors: Mayama Satoshi , Tamura Motohide , Hayashi Masahiko , Itoh Yoichi , Ishii Miki , Fukagawa Misato , Hayashi Saeko S. , Oasa Yumiko , Kudo Tomoyuki 
Published: March 2014

Abstract
We conducted subarcsecond near-infrared imaging observations of RNO 91 with CIAO (Coronagraphic Imager with Adaptive Optics) mounted on the 8.2 m Subaru telescope. We present our JHK band data along with optical images, which when considered together reveal a complex circumstellar structure. We examined the colors of associated nebulae and compared the geometry of the outflow/disk system suggested by our data with that already proposed on the basis of previous studies. Our K-band image shows bright circumstellar nebulosity detected within $\sim$2$^{\prime\prime}$ around the central source, while it is less conspicuous at shorter wavelengths. PA and the size of this red color nebulosity agree with those of the previously detected polarization disk. Agreements among these data indicate that this bright nebulosity region, which follows the reddening law, might be attributed to a disklike structure. At $J$ and optical wavelengths, several blue knotlike structures are detected around and beyond the bright circumstellar nebulosity. We suggest that these knotty reflection nebulae may represent disintegrating fragments of an infalling envelope. The three-color composite image has the appearance of arc-shaped nebulosity. We interpret these structures as being roots of a bipolar cavity opening toward the northeast and the southwest. The complex distribution of reflection nebulosity seen around RNO 91 appears to confirm the interpretation that this source is an object dispersing its molecular envelope while transitioning from protostar to T Tauri star.
Water Maser and Ammonia Survey toward IRAS Sources in the Galaxy I. H$_{2}$O Maser Data
Authors: Sunada Kazuyoshi , Nakazato Takeshi , Ikeda Norio , Hongo Satoshi , Kitamura Yoshimi , Yang Ji 
Published: March 2014

Abstract
We present H $_{2}$ O maser data from a survey toward IRAS sources in the Galaxy with the Nobeyama 45 m telescope. This survey had a 1$\sigma$ noise level as small as 0.24 Jy, resulting in one of the most sensitive water-maser surveys. The maximum distance of the masers to be detected by our survey is estimated to be 3 kpc for sources with $F_{\nu, \mathrm{1\,kpc}} &lt;$ 10 Jy and 10 kpc for those with 10 Jy $\le F_{\nu, \mathrm{1\,kpc}} &lt;$ 100 Jy, where $F_{\nu, \mathrm{1\,kpc}}$ is the maser flux density converted at a distance of 1 kpc. For strong masers with $F_{\nu, \mathrm{1\,kpc}} \ge$ 100 Jy, our survey could detect all sources in the Galaxy. We carried out a total of 2229 observations toward 1563 sources and detected water-maser emission toward 222 sources. Our survey newly found masers from 75 of the 222 sources. The maser spectra of the new sources are shown in addition to the line parameters of all the detected sources. Furthermore, we discovered an extremely high-velocity component with $V_\mathrm{LSR} = -146$kms$^{-1}$ toward a well-known source, NGC 7538 IRS 11. For the three sources of NGC 1333 IRAS 4A/B, IRAS 05329$-$0512, and 06053$-$0622, we succeeded to spatially separate multiple-velocity components.
Radiation Testing of Consumer High-Speed LSI Chips for the Next Space VLBI Mission
Authors: Wajima Kiyoaki , Kawaguchi Noriyuki , Murata Yasuhiro , Hirabayashi Hisashi 
Published: March 2014

Abstract
We carried out two types of radiation testing of high-speed LSI chips to test their suitability for use in wideband observations by the Japanese next space VLBI mission, VSOP-2. In a total ionization-dose experiment we monitored autocorrelation spectra, which were taken with irradiated LSI chips and the source current at intervals of up to 1000 hr from the ionization dose, but could not detect any change of these features for chips irradiated at the dose rates expected in the VSOP-2 mission. In a single event effect experiment, we monitored the cross-correlation phase and the power spectra between data from radiated and nonradiated devices, and the source current during the irradiation of heavy ions. We observed a few tens of single event upsets as discrete delay jumps for each LSI. We estimated the occurrence rate of single events in space to be between once every few days and once a month. No single event latch-up was seen in any of LSIs. These results show that the tested LSIs have sufficiently high tolerance for the environment for space VLBI observations.
Suzaku Observation of Diffuse X-Ray Emission from the Carina Nebula
Authors: Hamaguchi Kenji , Petre Robert , Matsumoto Hironori , Tsujimoto Masahiro , Holt Stephen S. , Ezoe Yuichiro , Ozawa Hideki , Tsuboi Yohko , Soong Yang , Kitamoto Shunji , Sekiguchi Akiko , Kokubun Motohide 
Published: March 2014

Abstract
We studied extended X-ray emission from the Carina Nebula taken with the Suzaku CCD camera XIS on 2005 August 29. The X-ray morphology, plasma temperature, and absorption to the plasma are consistent with the earlier Einstein results. The Suzaku spectra newly revealed emission lines from various species, including oxygen, but not from nitrogen. This result restricts the $\mathrm{N/O}$ ratio to be significantly low, compared with evolved massive stellar winds, suggesting that the diffuse emission originated in an old supernova remnant or a super shell produced by multiple supernova remnants. The X-ray spectra from the north and south of $\eta$ Car showed distinct differences between 0.3–2 keV. The south spectrum shows strong L-shell lines of iron ions and K-shell lines of silicon ions, while the north spectrum shows them weak in intensity. This means that the silicon and iron abundances are a factor of 2–4 higher in the south region than in the north region. The abundance variation may be produced by an SNR ejecta, or related to dust formation around the star-forming core.