bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Search for CO (J = 3–2) Emission from the Host Galaxy of GRB 980425 with the Atacama Submillimeter Telescope Experiment
Authors: Hatsukade Bunyo , Kohno Kotaro , Endo Akira , Tosaki Tomoka , Ohta Kouji , Sakamoto Seiichi , Kawai Nobuyuki , CortÉs Juan R. , Nakanishi Kouichiro , Okuda Takeshi , Muraoka Kazuyuki , Sakai Takeshi , Vreeswijk Paul M. , Ezawa Hajime , Yamaguchi Nobuyuki , Kamegai Kazuhisa , Kawabe Ryohei 
Published: March 2014

Abstract
We report on a deep search for $^{12}$CO ($J$=3–2) line emission from the host galaxy of GRB 980425 with the Atacama Submillimeter Telescope Experiment (ASTE). We observed five points of the galaxy, covering the entire region. After combining all of the spectra, we obtained a global spectrum with a rms noise level of 3.3 mK in the $T_{\mathrm{mb}}$ scale at a velocity resolution of 10 $\mathrm{km\ s^{-1}}$. No significant emission was detected, though we found a marginal emission feature in the velocity range corresponding to the redshift of the galaxy. We derived 3 $\sigma$ upper limits on the global properties: the velocity-integrated CO (3–2) intensity of $I_{\mathrm{CO}}$(3–2) $&lt; 0.26\ \mathrm{K\ km\ s^{-1}}$, by adopting a velocity width of $67\ \mathrm{km\ s^{-1}}$; an H$_2$ column density of $N(\mathrm{H_2}) &lt; 3 \times 10^{20} \mathrm{cm^{-2}}$; a molecular gas mass of $M(\mathrm{H_2}) &lt; 3 \times 10^8\ M_{\odot}$, by assuming a CO line luminosity to H$_2$ molecular gas mass conversion factor of $X_{\mathrm{CO}}=5.0\times10^{20}\ \mathrm{cm^{-2}\ (K\ km\ s^{-1})^{-1}}$; and a star-formation rate of SFR $&lt; 0.1\ M_{\odot}\ \mathrm{yr}^{-1}$, based on the Schmidt law. The SFR is consistent with the previous results of H$\alpha$ and mid-IR observations, thereby suggesting that there is no significant obscured star formation in the host galaxy of GRB 980425. This result implies that there is a variety of GRB hosts with regard to the presence of obscured star formation.
X-Ray Study of Temperature and Abundance Profiles of the Cluster of Galaxies Abell 1060 with Suzaku
Authors: Sato Kosuke , Yamasaki Noriko Y. , Ishida Manabu , Ishisaki Yoshitaka , Ohashi Takaya , Kawahara Hajime , Kitaguchi Takao , Kawaharada Madoka , Kokubun Motohide , Makishima Kazuo , Ota Naomi , Nakazawa Kazuhiro , Tamura Takayuki , Matsushita Kyoko , Kawano Naomi , Fukazawa Yasushi , Hughes John P. 
Published: March 2014

Abstract
We carried out observations of the central and 20$'$ east offset regions of the cluster of galaxies Abell 1060 with Suzaku. Spatially resolved X-ray spectral analysis has revealed temperature and abundance profiles of Abell 1060 out to 27$'\simeq 380\; h_{70}^{-1}$ kpc, which corresponds to $\sim$ 0.25 $r_{180}$. Temperature decrease of the intra-cluster medium from 3.4 keV at the center to 2.2 keV in the outskirt region was clearly observed. The abundances of Si, S, and Fe also decrease by more than 50% from the center to the outer region, while Mg shows a fairly constant abundance distribution at $\sim 0.7$ solar within $r \lesssim 17'$. O shows a lower abundance of $\sim 0.3$ solar in the central region ($r \lesssim 6'$), and indicates a similar feature with Mg; however, it is sensitive to the estimated contribution of the Galactic components of $kT_1 \sim$ 0.15 keV and $kT_2 \sim$ 0.7 keV in the outer annuli ($r \gtrsim 13'$). Systematic effects due to the point-spread function tails, contamination on the XIS filters, instrumental background, cosmic and/or Galactic X-ray background, and the assumed solar abundance tables were carefully examined. The results on the temperature and abundances of Si, S, and Fe are consistent with those derived by XMM-Newton at $r \lesssim$ 13$'$. The formation and metal-enrichment process of the cluster are discussed based on the present results.
Triaxial Analytical Potential-Density Pairs for Galaxies
Authors: Vogt Daniel , Letelier Patricio S. 
Published: March 2014

Abstract
We present two triaxial analytical potential-density pairs that can be viewed as generalized versions of the axisymmetric Miyamoto-Nagai and Satoh galactic models. These potential-density pairs may be useful models for galaxies with box-shaped bulges. The resulting mass-density distributions are everywhere non-negative and free from singularities. Also, a few numerically calculated orbits for the Miyamoto-Nagai-like triaxial potential are presented.
High-Resolution Mappings of the $l=1{\rlap{.}{^\circ}}3$ Complex in Molecular Lines: Discovery of a Proto-Superbubble
Authors: Tanaka Kunihiko , Kamegai Kazuhisa , Nagai Makoto , Oka Tomoharu 
Published: March 2014

Abstract
We report on the results of molecular line observations toward the $l=1{\rlap{\hskip.75pt{^\circ}}\hskip.75pt.\hskip1pt}3$ complex, an anomalous cloud complex in the central molecular zone of the Galaxy. The CO $J$=$3$–$2$ survey recently performed with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope has found that the complex has an enhanced CO $J$=$3$–$2$/$J$=$1$–$0$ intensity ratio. We have made high-resolution maps of the CO $J$=$1$–$0$, HCN $J$=$1$–$0, {\rm HCO^{+}} J$=$1$–$0$, SiO $J$=$1$–$0$, and $J$=$2$–$1$ lines with the Nobeyama 45 m telescope. The complex is found to be rich in shells and arcs of dense molecular gas. We identified 9 expanding shells in HCN maps and compact SiO features associated with the shells. The intensity ratios of HCN/CO, ${\rm HCO^{+}}$/CO, and CO $J$=$3$–$2$/$J$=$1$–$0$ are coherently enhanced by a factor of a few in gas with an LSR velocity higher than $110\ {\rm kms^{-1}}$. The high-velocity gas has a high density (${n_{\rm H}}\sim10^{4.5}\ {\rm cm^{-3}}$) and high SiO/$^{13}{\rm CO}$ intensity ratio, indicating that the gas was shocked. The typical HCN/${\rm HCO^{+}}$ intensity ratio is found to be 2.3, being higher by a factor of a few than those in the Galactic disk clouds. The typical kinetic energy and expansion time of the shells are estimated to be $10^{50.9\mbox{-}52.5}$ erg and $10^{4.6\mbox{-}5.3}$ yr, respectively. The kinetic energy could be furnished by multiple supernova and/or hypernova explosions at a rate of $10^{-3\mbox{-}-4}$ yr$^{-1}$. These estimates suggest that the expanding shells as a whole may be in the early stage of superbubble formation. This proto-superbubble may have originated in a massive cluster formation that took place $10^{6.8\mbox{-}7.6}\ {\rm yr}$ ago.
Fundamental Parameters and Elemental Abundances of 160 F–G–K Stars Based on OAO Spectrum Database
Authors: Takeda Yoichi 
Published: March 2014

Abstract
The properties of 160 F, G, and K disk dwarfs/subgiants (including 27 planet-host stars) mostly within $-0.6 \lesssim$ [Fe/H] $\lesssim +0.4$, the Okayama Astrophysical Observatory spectrum collection of which had been made open to the public recently, were extensively investigated with particular attention to determining (1) the mass and the age with the help of theoretical stellar evolution calculations, (2) the kinematic parameters of orbital motions in the Galaxy, and (3) the abundances of 15 elements (Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, and Zn) by analyzing the spectra in this database. The resulting characteristics are discussed in terms of several relevant topics of interest, such as a validity check for assuming LTE, the [X/Fe] vs. [Fe/H] diagram containing information on the chemical evolution of the Galactic disk, the age–metallicity–kinematics relation, and the difference/similarity between stars with and without planets.
Microwave Spectral Evolution of Solar Flares
Authors: Ning Zongjun , Ding Mingde 
Published: March 2014

Abstract
We analyze the time evolution of microwave spectral indices for 103 solar flares observed by Nobeyama Radio Polarimeters (NoRP) between 1998 and 2005. The microwave spectral index, $\gamma(t)$, is derived from the flux spectral index, $\delta(t)$. We assume a flux frequency dependence of the form $S(\nu,t) = F_0\nu^{\delta(t)}$ in the optically thin part, i.e., above the turnover frequency, $f_{\max}$. Here, $f_{\max}$ is defined as the frequency with the maximum flux among six discrete frequencies (i.e., 1, 2, 3.75, 9.4, 17, and 35 GHz). Based on NoRP observations, we find two typical types of solar flares with various microwave spectral behavior. Type I displays a soft–hard–soft pattern, while the type II flare follows a soft–hard–harder behavior in the rise–peak–decay phases at 35 GHz. Our statistical results of microwave flares confirm previous findings. Most microwave flares appear to be of type II (91 out of the present samples), which is different from the hard X-ray flares dominated by the soft–hard–soft property. Such a difference is an observational constraint for electron acceleration and transport theories in flare models.
Observations of Fragments Split from Nucleus B of Comet 73P/Schwassmann-Wachmann 3 with Subaru Telescope
Authors: Fuse Tetsuharu , Yamamoto Naotaka , Kinoshita Daisuke , Furusawa Hisanori , Watanabe Jun-ichi 
Published: March 2014

Abstract
We observed the nucleus B of Comet 73P/Schwassmann-Wachmann 3 on 2006 May 3, UT with a wide-field camera Suprime-Cam of the Subaru Telescope just before the closest approach to the Earth on 2006 May 12, UT. Since the fragmentation of nucleus B was reported in April of 2006, fresh fragments were expected to be detected. A total of 54 fragments were discovered within a 1$'$.60 $\times$ 1$'$.13 region, southwest of nucleus B. Carrying out aperture photometry for the fragments, we obtained the power-law index of the cumulative luminosity function, $\alpha=0.222$. If we assume that the CCD flux of a fragment is proportional to the cross section, the equation $q = 5\alpha + 1$ can be derived, where $q$ is the power-law index of the cumulative size distribution, and therefore $q$ = 2.1. Due to the large FOV of the camera ($34' \times 27'$), we might also be able to find fragments split from nucleus B before the perihelion passage in 2006. Upon searching for such fragments in the image, no object was found; since the approximate limiting magnitude is 24.2 mag, a bare nucleus (i.e., non-active comet) with 13.3 m in radius could be detected in the image; however, the real detection limit should be less than a radius of 13.3 m, because a comet at the same heliocentric distance as nucleus B of 1.1 AU would be active, and an active comet whose magnitude is 24.2 mag has a smaller nucleus than 13.3 m in radius due to the brightness of the dust coma.
Development of a Near-Infrared Echelle Spectrograph “NICE”
Authors: Yamamuro Tomoyasu , Kawabata Hironobu , Nedachi Ko , Nishimaki Yuichiro , Motohara Kentaro , Miyata Takashi , Pyo Tae-Soo , Takeyama Norihide , Tanaka Masuo 
Published: March 2014

Abstract
We developed a Near-Infrared Cross-dispersed Echelle spectrograph, “NICE”, which covers the wavelength range from 0.9$\mu$m to 2.4$\mu$m with four exposures, and has a wavelength resolution of $\lambda/\delta\lambda\sim2600$. These capabilities enable us to simultaneously evaluate the continuum level and intensity of various lines of a spectrum with high accuracy over a wide wavelength range. Since NICE is designed to be compact, by adopting a “white pupil” configuration and fully refractive lenses, we can carry out observations with small telescopes.
New Analytical Formulae for Optically Thin Accretion Flows
Authors: Watarai Ken-ya 
Published: March 2014

Abstract
In a previous paper, we described new analytic formulae for optically thick supercritical accretion flows (Watarai 2006, hereafter paper 1). Here, we present analytic formulae for optically thin one-temperature accretion flows including the advection-dominated regime, using the “semi-iterative” method, described in paper 1. Our analytic formulae have two real solutions. The first solution corresponds to advection-dominated accretion flow (ADAF), and the second solution corresponds to radiation-dominated accretion flow, described by Shapiro, Lightman, and Eardley (the so-called SLE model). Both solutions are given by a cubic equation for the advection parameter, $f$, which is the ratio of the advection cooling rate, $Q_{\rm adv}$, to the viscous heating rate, $Q_{\rm vis}$, i.e., $f=Q_{\rm adv}/Q_{\rm vis}$. Most previous studies assumed that $f$ is constant ($f \sim 1$ for the ADAF). However, it is clear that $f$ should be a function of the physical parameters of the radiative-cooling dominated regime. We found that the ratio $f$ can be written as a function of the radius, mass-accretion rate, and viscous parameter, $\alpha$. Using this formula, we can estimate the transition radius from the inner optically thin ADAF to the outer optically thick standard disk, which can be measured using observations of the quiescent state in black hole X-ray binaries.
Frequency Correlations of QPOs Based on a Disk Oscillation Model in Warped Disks
Authors: Kato Shoji 
Published: March 2014

Abstract
In previous papers, we proposed a model that high-frequency quasi-periodic oscillations (QPOs) observed in black-hole and neutron-star X-ray binaries are disk oscillations (inertial-acoustic and/or g-mode oscillations) resonantly excited on warped disks. In this paper we examine whether time variations of the QPOs and their frequency correlations observed in neutron-star X-ray binaries can be accounted for by this disk-oscillation model. By assuming that a warp has a time-dependent precession, we can well describe the observed frequency correlations among kHz QPOs and low-frequency QPOs over a wide range of frequencies.
Near-Infrared Polarimetry of the Eagle Nebula (M 16)
Authors: Sugitani Koji , Watanabe Makoto , Tamura Motohide , Kandori Ryo , Hough James H. , Nishiyama Shogo , Nakajima Yasushi , Kusakabe Nobuhiko , Hashimoto Jun , Nagayama Takahiro , Nagashima Chie , Kato Daisuke , Fukuda Naoya 
Published: March 2014

Abstract
We carried out deep and wide ($\sim$8$^{\prime}\times ^{\prime}$8) $JHK_{\rm s}$ imaging polarimetry in the southern region of the Eagle Nebula (M 16). The polarization intensity map reveals that two YSOs with near-IR reflection nebulae are located at the tips of two famous molecular pillars (Pillars 1 and 2) facing toward the exciting stars of M 16. The centrosymmetric polarization pattern are consistent with those around Class I objects having circumstellar envelopes, confirming that star formation is now taking place at the two tips of the pillars under the influence of UV radiation from the exciting stars. Polarization measurements of point sources show that magnetic fields are aligned along some of the pillars, but in a direction that is quite different to the global structure in M 16.
CO Observations of a FeLoBAL Quasar with an Hα $\alpha$ Absorption Line at z = 2.3
Authors: Ohta Kouji , Gaku Kiuchi , Kouichiro Nakanishi , Kentaro Aoki , Ikuru Iwata , Masayuki Akiyama , Naoyuki Tamura , Masataka Ando 
Published: March 2014

Abstract
SDSS J083942.11+380526.3 is an Iron Low-ionization Broad Absorption Line (FeLoBAL) quasar at $z=2.3$, and Aoki et al. (2006) recently found the presence of an H$\alpha$ absorption line in the broad H$\alpha$ emission line. Motivated by an idea that this quasar may be a huge molecular gas reservoir in the early phase of quasar evolution, we made CO($J=3$–$2$) observations of it using the Nobeyama Millimeter Array. No significant CO emission was detected; although an emission-like feature ($2.5\sigma$) was seen close ($\sim 2^{\prime\prime}$) to the quasar, we regard it as noise. The obtained 3$\sigma$ upper limit on the CO luminosity is $L^{\prime}_{{\rm CO}(J=3\mbox{-}2)} = 4.5 \times 10^{10}$ K km s$^{-1}$ pc$^2$, which corresponds to $M({\rm H}_2) = 3.6 \times 10^{10} M_{\odot}$ if we adopt CO-to-H$_2$ conversion factor of 0.8 $M_{\odot}$ (K km s$^{-1}$ pc$^2)^{-1}$. This upper limit is comparable to $L^{\prime}_{{\rm CO}(J=3\mbox{-}2)}$ (and thus the molecular gas mass) detected in quasars and BAL quasars at $z=1$-3, and no sign of the presence of the huge amount of molecular gas in this FeLoBAL quasar was obtained.
X-Ray Study of Discrete Sources in NGC 1808 with Chandra
Authors: Heike Kazunori , Awaki Hisamitsu 
Published: March 2014

Abstract
We analyzed discrete sources in a typical starburst galaxy, NGC 1808, with Chandra in order to study the relation between X-ray and star-forming activities. We detected thirty-eight X-ray sources with an X-ray luminosity ($L_{\rm X}$) of $\gt$ 10$^{37}$ erg s$^{-1}$ in the central 5$^{\prime}\times$5$^{\prime}$ (13.4 kpc $\times$ 13.4 kpc) region. About 90% of the hard X-rays previously detected with ASCA came from these discrete sources. Among the detected sources, sixteen sources had an $L_{\rm X}$ of $\gt$ 10$^{38}$ erg s$^{-1}$. The number of luminous sources is nearly equal to that of M 82, although their concentration into the central star-forming region is lower than that of M 82. There are several soft X-ray sources with a temperature of 0.6 keV in the central star-forming region. The X-ray properties of the soft sources are similar to those of a H II region, or a supernova remnant. The existence of both luminous sources and soft X-ray sources indicates the star-forming activity of NGC 1808. However, we detected only a few candidates of high-mass X-ray binaries that would be produced by enhanced star-forming activity. This may be due to the starburst age of NGC 1808.
The IRSF Magellanic Clouds Point Source Catalog
Authors: Kato Daisuke , Nagashima Chie , Nagayama Takahiro , Kurita Mikio , Koerwer Joel F. , Kawai Toshihide , Yamamuro Tomoyasu , Zenno Takahiro , Nishiyama Shogo , Baba Daisuke , Kadowaki Ryota , Haba Yasuaki , Hatano Hirofumi , Shimizu Hideyuki , Nishimura Mamiko , Nagata Tetsuya , Sato Shuji , Murai Yuka , Kawazu Takahiro , Nakajima Yasushi , Nakaya Hidehiko , Kandori Ryo , Kusakabe Nobuhiko , Ishihara Akika , Kaneyasu Nagisa , Hashimoto Jun , Tamura Motohide , Tanabé Toshihiko , Ita Yoshifusa , Matsunaga Noriyuki , Nakada Yoshikazu , Sugitani Koji , Wakamatsu Ken-ichi , Glass Ian S. , Feast Michael W. , Menzies John W. , Whitelock Patricia A. , Fourie Pieter , Stoffels John , Evans Geoff P. , Hasegawa Tetsuo 
Published: March 2014

Abstract
We present a near-infrared ($JHK_{\rm s}$) photometric catalog, including 14811185 point sources for a 40 deg$^2$ area of the Large Magellanic Cloud, 2769682 sources for an 11 deg$^2$ area of the Small Magellanic Cloud, and 434145 sources for a 4 deg$^2$ area of the Magellanic Bridge. The 10$\sigma$ limiting magnitudes are 18.8, 17.8, and 16.6 mag at $J, H$, and $K_{\rm s}$, respectively. The photometric and astrometric accuracies for bright sources are 0.03–0.04 mag and 0$\rlap {.}{^{\prime\prime}}$1, respectively. Based on the catalog, we also present (1) spatial distributions, (2) luminosity functions, (3) color–color diagrams, and (4) color–magnitude diagrams for point sources toward the Magellanic Clouds.
A Suggested Arrangement of Grooves for Enhancing the Return Loss Performance Characteristics of Submillimeter-Wave Corrugated Horns
Authors: Matsunaga Mayumi , Matsunaga Toshiaki 
Published: March 2014

Abstract
A new arrangement of grooves by which the return loss performance characteristics of submillimeter-wave corrugated horns have been greatly improved is presented. Corrugated horns equipped with grooves arranged as per the way introduced in this paper each have been found to be capable of radiating a field with return losses of $-$28 or less dB, while maintaining maximum cross-polarization levels of $-$45 or less dB within a frequency range of 385 GHz to 500 GHz. This is a performance level greater than the goal set for feed horns for radio telescopes. The reason for this enhancement of the return losses is because the part often referred to as the “mode-transforming section” has been formed differently, that is to say the grooves are arranged differently in this part than in the conventional mode-transforming section. Specifically, the number of grooves provided in this new mode-transforming section has been decreased vis-à-vis that of those in the conventional mode-transforming section, and these grooves are arranged with their depths varied in accordance with the angles of the section’s flares. Further, the structure of each groove has been so simplified that it is a parallelogram in cross section, and the part outside the mode-transforming section is provided with grooves that are in uniform depth and width being arranged at a regular interval. Despite the simplicity of the grooves, the return losses of submillimeter-wave corrugated horns have been greatly enhanced while their cross-polar radiation fields are maintained at low levels.
Absolute Proper Motions of H2O Masers Away from the Galactic Plane Measured with VERA in the “Superbubble” Region NGC 281
Authors: Sato Mayumi , Hirota Tomoya , Honma Mareki , Kobayashi Hideyuki , Sasao Tetsuo , Bushimata Takeshi , Choi Yoon Kyung , Imai Hiroshi , Iwadate Kenzaburo , Jike Takaaki , Kameno Seiji , Kameya Osamu , Kamohara Ryuichi , Kan-ya Yukitoshi , Kawaguchi Noriyuki , Kijima Masachika , Kim Mi Kyoung , 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 , Sato Katsuhisa , Shibata Katsunori M. , Shintani Motonobu , Tamura Yoshiaki , Tsushima Miyuki , Yamashita Kazuyoshi 
Published: March 2014

Abstract
We report on absolute proper-motion measurements of an H2O maser source in the NGC 281 West molecular cloud, which is located $\sim$ 320 pc above the Galactic plane and is associated with an H I loop extending from the Galactic plane. We conducted multi-epoch phase-referencing observations of the maser source with VERA (VLBI Exploration of Radio Astrometry) over a monitoring period of 6 months, since 2006 May. We find that the H2O maser features in NGC 281 West are systematically moving toward the southwest and further away from the Galactic plane with a vertical velocity of 20–30 km s$^{-1}$ at its estimated distance of 2.2–3.5 kpc. Our new results provide the most direct evidence that the gas in the NGC 281 region on the H I loop was blown out from the Galactic plane, most likely in a superbubble driven by multiple or sequential supernova explosions in the Galactic plane.
Relativistic Radiation Hydrodynamical Accretion-Disk Winds
Authors: Fukue Jun , Akizuki Chizuru 
Published: March 2014

Abstract
Accretion-disk winds blowing off perpendicular to a luminous disk are examined within the framework of fully special relativistic radiation hydrodynamics. The wind is assumed to be steady, vertical, and isothermal. Using a velocity-dependent variable Eddington factor, we can solve the rigorous equations of relativistic radiative hydrodynamics, and can obtain radiatively driven winds accelerated up to relativistic speeds. For less-luminous cases, disk winds are transonic types passing through saddle-type critical points, and the final speeds of the winds increase as the disk flux and/or the isothermal sound speed increase. For luminous cases, on the other hand, disk winds are always supersonic, since the critical points disappear due to the characteristic nature of the disk gravitational fields. The boundary between the transonic and supersonic types is located at around $\hat{F}_{\rm c} \sim 0.1 (\varepsilon+p)/(\rho c^2)/\gamma_{\rm c}$, where $\hat{F}_{\rm c}$ is the radiative flux at the critical point normalized by the local Eddington luminosity, $(\varepsilon+p)/(\rho c^2)$ is the enthalpy of the gas divided by the rest-mass energy, and $\gamma_{\rm c}$ is the Lorentz factor of the wind velocity at the critical point. In transonic winds, the final speed becomes 0.4–0.8$c$ for typical parameters, while it can reach $\sim c$ in supersonic winds.