bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Symbiotic System SS73 17 Seen with Suzaku
Authors: Smith Randall K. , Mushotzky Richard , Mukai Koji , Kallman Tim , Markwardt Craig B. , Tueller Jack 
Published: March 2014

Abstract
We observed with Suzaku the symbiotic star SS73 17, motivated by the discovery by the INTEGRAL satellite and the Swift BAT survey that it emits hard X-rays. Our observations showed a highly-absorbed X-ray spectrum with $N_{\rm H} \gt 10^{23}$cm$^{-2}$, equivalent to $A_{V} \gt 26$, although the source has B magnitude 11.3 and is also bright in UV. The source also shows strong, narrow iron lines including fluorescent FeK as well as FeXXV and FeXXVI. The X-ray spectrum can be fit with a thermal model including an absorption component that partially covers the source. Most of the equivalent width of the iron fluorescent line in this model can be explained as a combination of reprocessing in a dense absorber plus reflection off a white dwarf surface, but it is likely that the continuum is partially seen in reflection as well. Unlike other symbiotic systems that show hard X-ray emission (CH Cyg, RT Cru, T CrB, GX1$+$4), SS73 17 is not known to have shown nova-like optical variability, X-ray flashes, or pulsations, and has always shown faint soft X-ray emission. As a result, although it is likely a white dwarf, the nature of the compact object in SS73 17 is still uncertain. SS73 17 is probably an extreme example of the recently discovered and relatively small class of hard X-ray emitting symbiotic systems.
Suzaku Observations of Hercules X-1: Measurements of the Two Cyclotron Harmonics
Authors: Enoto Teruaki , Makishima Kazuo , Terada Yukikatsu , Mihara Tatehiro , Nakazawa Kazuhiro , Ueda Tsuyoshi , Dotani Tadayasu , Kokubun Motohide , Nagase Fumiaki , Naik Sachindra , Suzuki Motoko , Nakajima Motoki , Takahashi Hiromitsu 
Published: March 2014

Abstract
The accretion-powered pulsar Her X-1 was observed with Suzaku twice in its main-on state, on 2005 October 5-6 and 2006 March 29-30, for a net exposure of 30.5ks and 34.4ks, respectively. In the 2005 and 2006 observations, the source was detected at an average 10-30keV intensity of 290mCrab and 230mCrab, respectively. The intrinsic pulse period was measured on both occasions at 1.23776s by HXD-PIN, after barycentric and binary corrections. The pulse phase-averaged spectra in the energy range above 10keV were well fitted by the “Negative and Positive power-law times EXponential” (NPEX) model, multiplied by a fundamental cyclotron resonance scattering feature at $\sim$36keV, which appears very significantly in the HXD-PIN data. The resonance profiles were successfully reproduced by a Lorentzian-type scattering cross section, rather than by a Gaussian-type alternative. The pulse phase-averaged HXD-GSO data, covering 50-120keV, are featureless. However, in a differential spectrum between the pulse-decay phase and off-pulse phase, the second-harmonic cyclotron resonance was detected in the GSO data at $\sim$73keV, with a depth of 1.6$_{-0.7}^{+0.9}$. This makes Her X-1 a 6th pulsar with established second-harmonic resonance. The implications of these results are briefly discussed.
Suzaku Observations of the North Polar Spur: Evidence for Nitrogen Enhancement
Authors: Miller Eric D. , Tsunemi Hiroshi , Bautz Mark W. , McCammon Dan , Fujimoto Ryuichi , Hughes John P. , Katsuda Satoru , Kokubun Motohide , Mitsuda Kazuhisa , Porter F. Scott , Takei Yoh , Tsuboi Yohko , Yamasaki Noriko Y. 
Published: March 2014

Abstract
We present observations of the North Polar Spur (NPS) using the X-ray Imaging Spectrometer (XIS) aboard the Suzaku X-ray satellite. The NPS is a large region of enhanced soft X-ray and radio emission projected above the plane of the Galaxy, likely produced by a series of supernovae and stellar winds from the nearby Sco-Cen OB association. The exceptional sensitivity and spectral resolution of the XIS below 1keV allow unprecedented probing of low-energy spectral lines, including CVI (0.37keV) and NVII (0.50keV), and we have detected highly-ionized nitrogen toward the NPS for the first time. For this single pointing toward the brightest 3/4keV emission ($l =$ 26°.8, $b =$$+$22°.0), the best-fit NPS emission model implies a hot ($kT \approx 0.3$keV), collisional ionization equilibrium (CIE) plasma with depleted C, O, Ne, Mg, and Fe abundances of less than 0.5solar, but an enhanced N abundance, with N$/$O $=$$(4.0^{+0.4}_{-0.5})$ times solar. The temperature and total thermal energy of the gas suggest heating by one or more supernovae, while the enhanced nitrogen abundance is best explained by enrichment from stellar material that has been processed by the CNO cycle. Due to the time required to develop AGB stars, we conclude that this N$/$O enhancement cannot be caused by the Sco-Cen OB association, but may result from a previous enrichment episode in the solar neighborhood.
Absolute Photometric Calibration of the Infrared Camera (IRC) aboard AKARI
Authors: TanabÉ Toshihiko , Sakon Itsuki , Cohen Martin , Wada Takehiko , Ita Yoshifusa , Ohyama Youichi , Oyabu Shinki , Uemizu Kazunori , Takagi Toshinobu , Ishihara Daisuke , Kim Woojung , Ueno Munetaka , Matsuhara Hideo , Onaka Takashi 
Published: March 2014

Abstract
The absolute photometric calibration of imaging observations with the Infrared Camera (IRC) aboard the AKARI satellite was performed by monitoring the same stars regularly and by observing a set of standard stars. By our monitoring observations, we confirmed that all channels of the IRC were stable to within 4% and that their sensitivities were constant until the liquid helium was exhausted. Using the data of these repeated observations, we evaluated the intrinsic errors as a function of the brightnesses of objects and found that the errors increase rapidly toward fainter objects. We also checked the consistency between short and long exposure times, and confirmed that the data sampling had been executed as designed. Finally, by comparing the estimated in-band flux densities and the observed data values of standard stars, we obtained conversion factors to the absolute flux densities of all the band/exposure configurations. Their absolute uncertainties are estimated to be less than 6%.
Far-Infrared Properties of Blue Compact Dwarf Galaxies Observed with AKARI/Far-Infrared Surveyor (FIS)
Authors: Hirashita Hiroyuki , Kaneda Hidehiro , Onaka Takashi , Suzuki Toyoaki 
Published: March 2014

Abstract
We report on the basic far-infrared (FIR) properties of eight blue compact dwarf galaxies (BCDs) observed by AKARI. We have measured the fluxes at the four FIS bands (wavelengths of 65$\mu$m, 90$\mu$m, 140$\mu$m, and 160$\mu$m). Based on these fluxes, we have estimated basic quantities of dust: dust temperature, dust mass, and total FIR luminosity. We find that the typical dust temperature of the BCD sample is systematically higher than that of normal spiral galaxies, although there is a large variety. The interstellar radiation field estimated from the dust temperature ranges up to 100-times the galactic value. This confirms the concentrated star-forming activity in BCDs. The star-formation rate can be evaluated from the FIR luminosity as 0.01-0.5$M_{\odot}$yr$^{-1}$. Combining this quantity with the gas mass taken from the literature, we have estimated the gas consumption timescales (gas mass divided by the star-formation rate), which have proved to span a wide range from 1Gyr to 100Gyr. A natural interpretation of this large variety can be provided by intermittent star-formation activity. We finally show the relation between dust-to-gas ratio and metallicity (we utilized our estimate of dust mass, and took other necessary quantities from the literature). There is a positive correlation between dust-to-gas ratio and metallicity, as expected from chemical evolution models.
The Atacama Compact Array (ACA)
Authors: Iguchi Satoru , Morita Koh-Ichiro , Sugimoto Masahiro , Vilaró Baltasar Vila , Saito Masao , Hasegawa Tetsuo , Kawabe Ryohei , Tatematsu Ken’ichi , Sakamoto Seiichi , Kiuchi Hitoshi , Okumura Sachiko K. , Kosugi George , Inatani Junji , Takakuwa Shigehisa , Iono Daisuke , Kamazaki Takeshi , Ogasawara Ryusuke , Ishiguro Masato 
Published: March 2014

Abstract
For realizing high fidelity of imaging with mosaicing observations, the Atacama Large Millimeter/submillimeter Array (ALMA) consists of a homogeneous array of 12 m antennas (12 m Array) and the Atacama Compact Array (ACA) in order to cover all spatial frequency Fourier components of the brightness distribution of observed sources. The array is located at an altitude site of about 5000 m with an operating wavelength range of 0.3 to 3 mm. ACA is an array composed of four 12 m dishes [TP (Total Power) Array] and twelve 7 m dishes (7 m Array). The 7 m Array has a very compact configuration to take short-baseline data corresponding to the low spatial frequency Fourier components. The 7 m Array has two configurations extended over 30-50 m to avoid shadowing at low elevation. The scientific importances and operation concepts of ACA, and the system design of ACA and its performance are presented in this paper.
Uniting the Quiescent Emission and Burst Spectra of Magnetar Candidates
Authors: Nakagawa Yujin E. , Yoshida Atsumasa , Yamaoka Kazutaka , Shibazaki Noriaki 
Published: March 2014

Abstract
Spectral studies of quiescent emission and bursts of magnetar candidates based on XMM-Newton, Chandra, and Swift data are presented. Spectra of both the quiescent emission and the burst for most magnetar candidates are reproduced by a photoelectrically absorbed two-blackbody function (2BB). There is a strong correlation between the lower and higher temperatures of 2BB ($kT_{\mathrm{LT}}$ and $kT_{\mathrm{HT}}$) for the magnetar candidates of which the spectra are well reproduced by 2BB. In addition, a square of radius for $kT_{\mathrm{LT}}$ ($R_{\mathrm{LT}}^2$) is well correlated with a square of radius for $kT_{\mathrm{HT}}$ ($R_{\mathrm{HT}}^2$). The ratio $kT_{\mathrm LT}/kT_{\mathrm HT}$$\approx$ 0.4 is nearly constant irrespective of the objects and/or emission types (i.e., the quiescent emission and the burst). This would imply that an emission mechanism is common among the magnetar candidates. The relation between the quiescent emission and the burst might be analogous to a relation between the solar microflare and the solar flare. Three anomalous X-ray pulsars (AXPs) (4U0142$+$614, 1RXSJ170849.0$-$400910, and 1E 2259$+$586) seem to have an excess above $\sim$7 keV, which well agrees with a nonthermal hard component discovered by the International Gamma-Ray Astrophysics Laboratory (INTEGRAL).
Search for Near-Infrared Pulsation of the Anomalous X-Ray Pulsar 4U 0142$+$61
Authors: Morii Mikio , Kobayashi Naoto , Kawai Nobuyuki , Terada Hiroshi , Tanaka Yasuyuki T. , Kitamoto Shunji , Shibazaki Noriaki 
Published: March 2014

Abstract
We have searched for pulsation of the anomalous X-ray pulsar (AXP) 4U 0142$+$61 in the $K^\prime$ band ($\lambda_{\rm eff}$$=$ 2.11$\mu$m) using the fast-readout mode of Infrared Camera and Spectrograph (IRCS) at the Subaru 8.2 m telescope. We found no significant signal at the pulse frequency expected by the precise ephemeris based on an X-ray monitoring observation with RXTE. Nonetheless, we obtained the best upper limit of 17% (90% C.L.) for the root-mean-square pulse fraction in the $K^\prime$ band. Combined with the $i^\prime$ band pulsation (Dhillon et al. 2005, MNRAS, 363, 609), the slope of the pulsed component ($F_\nu \propto \nu^\alpha$ in units of Jy) was constrained to $\alpha$$&gt;$$-$0.87 (90% C.L.) for an interstellar extinction of $A_{V}$$=$ 3.5.
Magnetic Structure of Umbral Dots Observed with the Hinode Solar Optical Telescope
Authors: Watanabe Hiroko , Kitai Reizaburo , Ichimoto Kiyoshi , Katsukawa Yukio 
Published: March 2014

Abstract
A high-resolution, seeing-free spectroscopic observation of a decaying sunspot was made with the Solar Optical Telescope aboard the Hinode satellite. The target was NOAA 10944, located in the west side of the solar surface from 2007 March 2 to March 4. The umbra included many umbral dots (UDs) with a size of $\sim$300 km in continuum light. We report on the magnetic structures and Doppler velocity fields around UDs, based on the Milne–Eddington inversions of the two iron absorption lines at 6302 Å. Histograms of the magnetic field strength (B), inclination angle (i), and Doppler velocity (v) of UDs showed a center-to-limb variation; observed at the disk center, the UDs had (i) slightly smaller field strength ($\Delta B$$=$$-$17 Gauss) and (ii) relative blue shifts ($\Delta v$$=$ 28 ms$^{-1}$) compared to their surroundings. When the sunspot got close to the limb, UDs and their surroundings showed almost no difference in the magnetic and Doppler values. This center-to-limb variation can be understood by the formation height difference in a cusp-shaped magnetized atmosphere around UDs, due to the weakly magnetized hot gas intrusion. In addition, some UDs showed the oscillatory light curves with multiple peaks separated around 10 min, which may indicate the presence of the oscillatory convection. We discuss our results within the frameworks of two theoretical models: the monolithic model (Schüssler & Vögler 2006, ApJ, 641, L73) and the field-free intrusion model (Spruit & Scharmer 2006, A&A, 447, 343).
Optically Thick Outflows of Supercritical Accretion Discs: Radiative Diffusion Approach
Authors: Abolmasov Pavel , Karpov Sergey , Kotani Taro 
Published: March 2014

Abstract
Highly supercritical accretion discs are probable sources of dense optically thick axisymmetric winds. We introduce a new approach based on diffusion approximation radiative transfer in a funnel geometry, and obtain an analytical solution for the energy density distribution inside the wind, assuming that all of the mass, momentum and energy are injected well inside the spherization radius. This allows us to derive the spectrum of the emergent emission for various inclination angles. We show that self-irradiation effects play an important role in altering the temperature of the outcoming radiation by about 20%, and the apparent X-ray luminosity by a factor of 2–3. The model has been successfully applied to two ULXs. The basic properties of the high ionization He ii-regions found around some ULXs are also easily reproduced in our models.
Molecular Superbubbles and Outflows from the Starburst Galaxy NGC 2146
Authors: Tsai An-Li , Matsushita Satoki , Nakanishi Kouichiro , Kohno Kotaro , Kawabe Ryohei , Inui Tatsuya , Matsumoto Hironori , Tsuru Takeshi G. , Peck Alison B. , Tarchi Andrea 
Published: March 2014

Abstract
We present results from a deep (1$\sigma$$=$ 5.7 mJy beam$^{-1}$ per 20.8 kms$^{-1}$ velocity channel) $^{12}$CO(1–0) interferometric observation of the central 60$^{\prime\prime}$ region of the nearby edge-on starburst galaxy NGC 2146, observed with the Nobeyama Millimeter Array. Two diffuse expanding molecular superbubbles and one molecular outflow were successfully detected. One molecular superbubble, with a size of $\sim$1 kpc and an expansion velocity of $\sim$50 kms$^{-1}$, is located below the galactic disk; a second molecular superbubble, with a size of $\sim$700 pc and an expansion velocity of $\sim$35 kms$^{-1}$, is also seen in the position-velocity diagram; the molecular outflow is located above the galactic disk with an extent of $\sim$2 kpc, expanding with a velocity of up to $\sim$200 kms$^{-1}$. The molecular outflow has an arc-like structure, and is located at the front edge of the soft X-ray outflow. In addition, the kinetic energy ($\sim$3 $\times$ 10$^{55}$erg) and the pressure ($\sim$1 $\times$ 10$^{-12\pm1}$dyncm$^{-2}$) of the molecular outflow are comparable to, or smaller than, that of the hot thermal plasma, suggesting that the hot plasma pushes the molecular gas out from the galactic disk. Inside the $\sim$1 kpc size molecular superbubble, diffuse soft X-ray emission seems to exist. However, since the superbubble lies behind the inclined galactic disk, it is largely absorbed by the molecular gas.
Search for Sc-K Line Emission from RX J0852.0$-$4622 Supernova Remnant with Suzaku
Authors: Hiraga Junko S. , Kobayashi Yusuke , Tamagawa Toru , Hayato Asami , Bamba Aya , Terada Yukikatsu , Petre Robert , Katagiri Hideaki , Tsunemi Hiroshi 
Published: March 2014

Abstract
We searched for evidence of line emission around 4 keV from the northwestern rim of the supernova remnant RX J0852.0$-$4622 using Suzaku XIS data. Several papers have reported on the detection of an emission line around 4.1 keV from this region of the sky. This line would arise from $K$-band fluorescence by $^{44}$Sc, the immediate decay product of $^{44}$Ti. We performed spectral analysis for the entire portion of the NW rim of the remnant within the XIS field of view, as well as various regions corresponding to regions of published claims of line emission. We found no line emission around 4.1 keV anywhere, and are able to set a restrictive upper limit to the X-ray flux: 1.1 $\times$ 10$^{-6}$s$^{-1}$cm$^{-2}$ for the entire field. For every region, our flux upper limit falls below that of the previously claimed detection. Therefore, we conclude that, to date, no definite X-ray line feature from Sc-K emission has been detected in the NW rim of RX J0852.0$-$4622. Our negative-detection supports the recent claim that RX J0852$-$4622 is neither young (1700–4000 yr) nor nearby ($\sim$750 pc).
Ejecta Distributions of Heavy Elements in the Cygnus Loop
Authors: Uchida Hiroyuki , Tsunemi Hiroshi , Katsuda Satoru , Kimura Masashi , Kosugi Hiroko 
Published: March 2014

Abstract
We analyzed the metal distribution of the Cygnus Loop using 14 and 7 pointing observation data obtained by the Suzaku and XMM-Newton observatories, respectively. The spectral analysis shows that all of the spectra are well fitted by a two-$kT_{\rm e}$ nonequilibrium ionization plasma model, as shown by earlier observations. From the best-fit parameters of the high-$kT_{\rm e}$ component, we calculated the emission measures about various elements, and showed the metal distribution of the ejecta component. We found that the distributions of Si and Fe are centered south of the geometric center toward the blow-out region. From the best-fit parameters, we also estimated the progenitor mass of the Cygnus Loop from our field of view (FOV) and the metal-rich region with a radius of 25$^\prime$ from the metal center. The result obtained from the metal circle is similar to that obtained from our entire FOV, which suggests a mixing of the metal. From the results, the mass of the progenitor star was estimated at 12-15$M_{\odot}$.
Photometric Studies of a WZ Sge-Type Dwarf Nova Candidate, ASAS 160048$-$4846.2
Authors: Soejima Yuichi , Imada Akira , Nogami Daisaku , Kato Taichi , Monard Berto 
Published: March 2014

Abstract
We report on our time-resolved CCD photometry during the 2005 June superoutburst of a WZ Sge-type dwarf nova candidate, ASAS 160048$-$4846.2. The ordinary superhumps of the object underwent a complex evolution during the superoutburst. The superhump amplitude experienced a regrowth and had two peaks. The superhump period decreased when the superhump amplitude reached the first maximum, subsequently increased gradually until the second maximum of the amplitude, and finally decreased again. Investigating other SU UMa-type dwarf novae, which show an increase in superhump period, we found the same trend of the superhump evolution in superoutbursts of them. We speculate that the superhump regrowth in the amplitude has a direct relation to the increase in superhump period, and all SU UMa-type dwarf novae with a superhump regrowth follow the same evolution of the ordinary superhumps as that of ASAS 160048$-$4846.2.
Suzaku-WAM, Konus-Wind, and Swift-BAT Observations of Prompt Emission of the High-Redshift GRB 050904
Authors: Sugita Satoshi , Yamaoka Kazutaka , Ohno Masanori , Tashiro Makoto S. , Nakagawa Yujin E. , Urata Yuji , Pal’shin Valentin , Golenetskii Sergei , Sakamoto Takanori , Cummings Jay , Krimm Hans , Stamatikos Michael , Parsons Ann , Barthelmy Scott , Gehrels Neil 
Published: March 2014

Abstract
We present the results of the high-redshift GRB 050904 at z$=$ 6.295 from joint spectral analysis among Swift-BAT, Konus-Wind, and Suzaku-WAM, covering a wide energy range of 15–5000 keV. The $\nu F_{\nu}$ spectrum peak energy, $E_{\rm peak}$, was measured at 314$^{+173}_{-89}$keV, corresponding to 2291$^{+1263}_{-634}$keV in the source frame, and the isotropic equivalent radiated energy, $E_{\rm iso}$, was estimated to be 1.04$^{+0.25}_{-0.17}$$\times$ 10$^{54}$erg. Both are among the highest values that have ever been measured. GRBs with such a high $E_{\rm iso}$ ($\sim$10$^{54}$erg) might be associated with prompt optical emission. The derived spectral and energetic parameters are consistent with the correlation between the rest-frame $E_{\rm p,i}$ and the $E_{\rm iso}$ (Amati relation), but not with the correlation between the intrinsic peak energy $E_{\rm p,i}$ and the collimation-corrected energy $E_{\gamma}$ (Ghirlanda relation), unless the density of the circumburst environment of this burst is much larger than the nominal value, as suggested by other wavelength observations. We also discuss the possibility that this burst is an outlier in the correlation between $E_{\rm p,i}$ and the peak luminosity $L_{\rm p}$ (Yonetoku relation).
Chemical Evolution of Zinc in the Galaxy
Authors: Saito Yu-ji , Takada-Hidai Masahide , Honda Satoshi , Takeda Yoichi 
Published: March 2014

Abstract
The local thermodynamic equilibrium (LTE) abundances of zinc (Zn) of our sample of 35 metal-poor stars were explored in the range of $-$3.0 $&lt;$ [Fe$/$H] $&lt;$ 0.0. Based on a combination of our Zn abundances and those obtained in the literature, the behavior of Zn was investigated in the range of $-$4.2 $&lt;$ [Fe$/$H] $&lt;$ $+$0.5. The main results are as follows: (1) No clear separation in [Zn$/$Fe] behavior was found between halo, thick disk, and thin disk stars in our sample. (2) The decreasing trend of [Zn$/$Fe] with the increase of [Fe$/$H] was found to be confirmed to $-$4.2 $&lt;$ [Fe$/$H] $\le$ $-$2.0, and to be explained by a chemical evolution model constructed with models of core-collapse supernovae (SNe) II or hypernovae (HNe) of Population III stars. (3) In $-$2.0 $&lt;$ [Fe$/$H] $&lt;$ $+$0.5, [Zn$/$Fe] follows a nearly flat trend with a slight enhancement of $\sim+$0.07 dex up to [Fe$/$H] $=$ $-$1.0, and shows the more enhanced trend in $-$1.0 $&lt;$ [Fe$/$H] $\le$ $-$0.5, and then gradually decreases to an almost solar value in [Fe$/$H] $&gt;$ $-$0.5. This trend is better explained by a chemical evolution model constructed with models of normal SNe II, HNe, and SNe Ia, in which the metallicity effect and the single-degenerate scenario of the SNe Ia model are incorporated.