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1. Evolution of X-ray and optical rapid variability during the low/hard state in the 2018 outburst of MAXI J1820+070 = ASASSN-18ey

Author

Kimura, Mariko, Negoro, Hitoshi, Yamada, Shinya, Iwakiri, Wataru, Sako, Shigeyuki, and Ohsawa, Ryou

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We performed shot analyses of X-ray and optical sub-second flares observed during the low/hard state of the 2018 outburst in MAXI J1820$+$070. Optical shots were less spread than X-ray shots. The amplitude of X-ray shots was the highest at the onset of the outburst, and they faded at the transition to the intermediate state. The timescale of shots was $\sim$0.2 s, and we detected the abrupt spectral hardening synchronized with this steep flaring event. The time evolution of optical shots was not similar to that of X-ray shots. These results suggest that accreting gas blobs triggered a series of magnetic reconnections at the hot inner accretion flow in the vicinity of the black hole, which enhanced X-ray emission and generated flaring events. The rapid X-ray spectral hardening would be caused by this kind of magnetic activity. Also, the synchrotron emission not only at the hot flow but also at the jet plasma would contribute to the optical rapid variability. We also found that the low/hard state exhibited six different phases in the hardness-intensity diagram and the correlation plot between the optical flux and the X-ray hardness. The amplitude and duration of X-ray shots varied in synchrony with these phases. This time variation may provide key information about the evolution of the hot flow, the low-temperature outer disk, and the jet-emitting plasma., Comment: 16 pages, 7 figures, accepted for publication in PASJ

Published
2024
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2. Kinematics of Supernova Remnants Using Multiepoch Maximum Likelihood Estimation: Chandra Observation of Cassiopeia A as an Example

Author

Sakai, Yusuke, Yamada, Shinya, Sato, Toshiki, Hayakawa, Ryota, and Kominato, Nao

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Decadal changes in a nearby supernova remnant (SNR) were analyzed using a multiepoch maximum likelihood estimation (MLE) approach. To achieve greater accuracy in capturing the dynamics of SNRs, kinematic features and point-spread function effects were integrated into the MLE framework. Using Cassiopeia A as a representative example, data obtained by the Chandra X-ray Observatory in 2000, 2009, and 2019 were utilized. The proposed multiepoch MLE was qualitatively and quantitatively demonstrated to provide accurate estimates of various motions, including shock waves and faint features, across all regions. To investigate asymmetric structures, such as singular components that deviate from the direction of expansion, the MLE method was extended to combine multiple computational domains and classify kinematic properties using the $k$-means algorithm. This approach allowed for the mapping of different physical states onto the image, and one classified component was suggested to interact with circumstellar material by comparison with infrared observations from the James Webb Space Telescope. Thus, this technique will help quantify the dynamics of SNRs and discover their unique evolution., Comment: Accepted for publication in ApJ. The paper is 20 pages long with 13 figures. Animations for Fig. 8 and Fig. 9, which provide a visual illustration of the results, are available in ApJ

Published
2024
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3. Polarized X-rays Correlated with Short--Timescale Variability of Cygnus X-1

Author

Ninoyu, Kaito, Uchida, Yuusuke, Yamada, Shinya, Kohmura, Takayoshi, Igarashi, Taichi, Hayakawa, Ryota, and Kawamura, Tenyo

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We systematically investigate the variability of polarized X-rays on a timescale of a few seconds in the low/hard state of the black hole binary Cygnus X-1. The correlation between polarization degrees and angles with X-Ray intensity was analyzed using data collected by the Imaging X-ray Polarimetry Explorer (IXPE) in June 2022. Given that X-Ray variability in the low/hard state of Cygnus X-1 is non-periodic, flux peaks were aggregated to suppress statistical fluctuations. We divided the temporal profiles of these aggregated flux peaks into seven time segments and evaluated the polarization for each segment. The results reveal that the polarization degree was 4.6\%$\pm$1.2 and 5.3\%$\pm$1.2 before and after the peak, respectively, but decreased to 3.4\%$\pm$1.1 and 2.7\%$\pm$1.1 in the segments including and immediately following the peak. Furthermore, the polarization angle exhibited a slight shift from approximately 30$^{\circ}$ to $\sim$40$^{\circ}$ before and after the peak. These findings suggest that the accretion disk contracts with increasing X-Ray luminosity, and the closer proximity of the X-Ray emitting gas to the black hole may lead to reduced polarization.

Published
2024
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5. Richardson-Lucy deconvolution with a spatially Variant point-spread function of Chandra: Supernova Remnant Cassiopeia A as an Example

Author

Sakai, Yusuke, Yamada, Shinya, Sato, Toshiki, Hayakawa, Ryota, Higurashi, Ryota, and Kominato, Nao

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Richardson-Lucy (RL) deconvolution is one of the classical methods widely used in X-ray astronomy and other areas. Amid recent progress in image processing, RL deconvolution still leaves much room for improvement under a realistic situations. One direction is to include the positional dependence of a point-spread function (PSF), so-called RL deconvolution with a spatially variant PSF (RL$_{\rm{sv}}$). Another is the method of estimating a reliable number of iterations and their associated uncertainties. We developed a practical method that incorporates the RL$_{\rm{sv}}$ algorithm and the estimation of uncertainties. As a typical example of bright and high-resolution images, the Chandra X-ray image of the supernova remnant Cassiopeia~A was used in this paper. RL$_{\rm{sv}}$ deconvolution enables us to uncover the smeared features in the forward/backward shocks and jet-like structures. We constructed a method to predict the appropriate number of iterations by using statistical fluctuation of the observed images. Furthermore, the uncertainties were estimated by error propagation from the last iteration, which was phenomenologically tested with the observed data. Thus, our method is a practically efficient framework to evaluate the time evolution of the remnants and their fine structures embedded in high-resolution X-ray images., Comment: 9 pages, 8 figures

Published
2023
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8. MASTER OT J030227.28+191754.5: a dwarf nova at a massive oxygen-neon white-dwarf system ?

Author

Kimura, Mariko, Kashiyama, Kazumi, Shigeyama, Toshikazu, Tampo, Yusuke, Yamada, Shinya, and Enoto, Teruaki

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract

We present timing and spectral analysis results of the {\it NICER} and {\it NuSTAR} observations of the dwarf nova MASTER OT J030227.28$+$191754.5 during the 2021--2022 outburst. The soft X-ray component was found to be dominated by blackbody radiation with a temperature of $\sim$30 eV and also showed prominent oxygen and neon emission lines. The blackbody luminosity exceeded 10$^{34}$ ergs s$^{-1}$, which is consistent with theoretical predictions, and then decreased more than an order of magnitude in 3.5 days. The inferred abundances of oxygen and neon in the optically-thin coronal region surrounding the central white dwarf (WD) are several times higher than the respective solar values. Although inconclusive, the abundance enrichment may originate from the WD, indicating that it may be mainly composed of oxygen and neon. Assuming that the blackbody radiation comes from the belt-shaped boundary layer between the WD and the accretion disk, we estimated the WD radius to be $(2.9\pm1.1)\times10^{8}$ cm, which corresponds to the WD mass range of 1.15--1.34 $M_{\odot}$. If the accretion continues for another $\sim$Gyr, the WD may experience an accretion-induced collapse into a neutron star and form a so-called black-widow pulsar system., Comment: Accepted for publication in ApJ. 15 pages, 8 figures, 3 tables

Published
2023
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9. Absolute Energy Measurements with Superconducting Transition-Edge Sensors for Muonic X-ray Spectroscopy at 44 keV

Author

Yan, Daikang, Weber, Joel C., Guruswamy, Tejas, Morgan, Kelsey M., O'Neil, Galen C., Wessels, Abigail L., Bennett, Douglas A., Pappas, Christine G., Mates, John A., Gard, Johnathon D., Becker, Daniel T., Fowler, Joseph W., Swetz, Daniel S., Schmidt, Daniel R., Ullom, Joel N., Okumura, Takuma, Isobe, Tadaaki, Azuma, Toshiyuki, Okada, Shinji, Yamada, Shinya, Hashimoto, Tadashi, Quaranta, Orlando, Miceli, Antonino, Gades, Lisa M., Patel, Umeshkumar M., Paul, Nancy, Bian, Guojie, and Indelicato, Paul

Subjects
Physics - Instrumentation and Detectors
Abstract

Superconducting transition-edge sensor (TES) microcalorimeters have great utility in x-ray applications owing to their high energy resolution, good collecting efficiency and the feasibility of being multiplexed into large arrays. In this work, we develop hard x-ray TESs to measure the absolute energies of muonic-argon ($\mu$-Ar) transition lines around 44 keV and 20 keV. TESs with sidecar absorbers of different heat capacities were fabricated and characterized for their energy resolution and calibration uncertainty. We achieved ~ 1 eV absolute energy measurement accuracy at 44 keV, and < 12 eV energy resolution at 17.5 keV.

Published
2022
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10. X-ray Studies of the Inverted Ejecta Layers in the Southeast Area of Cassiopeia A

Author

Tsuchioka, Tomoya, Sato, Toshiki, Yamada, Shinya, and Uchiyama, Yasunobu

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The central strong activities in core-collapse supernovae expect to produce the overturning of the Fe- and Si/O-rich ejecta during the supernova explosion based on multi-dimensional simulations. X-ray observations of the supernova remnant Cassiopeia A have indicated that the Fe-rich ejecta lies outside the Si-rich materials in the southeastern region, which is consistent with the hypothesis on the inversion of the ejecta. We investigate the kinematic and nucleosynthetic properties of the inverted ejecta layers in detail to understand its formation process using the data taken by the Chandra X-ray Observatory. Three-dimensional velocities of Fe- and Si/O-rich ejecta are obtained as $>$4,500 km s$^{-1}$ and $\sim$2,000--3,000 km s$^{-1}$, respectively, by combining proper motion and line-of-sight velocities, indicating that the velocity of the Si/O-rich ejecta is slower than that of the Fe-rich ejecta since the early stage of the explosion. To constrain their burning regime, the Cr/Fe mass ratios are evaluated as $0.51_{-0.10}^{+0.11}$% in the outermost Fe-rich region and $1.24 ^{+0.19}_{-0.20}$% in the inner Fe/Si-rich region, suggesting that the complete Si burning layer is invertedly located to the incomplete Si burning layer. All the results support the ejecta overturning at the early stages of the remnant's evolution or during the supernova explosion of Cassiopeia A., Comment: ApJ accepted. 11 pages, 7 figures

Published
2022
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11. Discovery of Stable Titanium at the Northeastern Jet of Cassiopeia A: Need for a Weak Jet Mechanism?

Author

Ikeda, Takuma, Uchiyama, Yasunobu, Sato, Toshiki, Higurashi, Ryota, Tsuchioka, Tomoya, and Yamada, Shinya

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The origin of the jet-like structures observed in Cassiopeia A is still unclear, although it seems to be related to its explosion mechanism. X-ray observations of the characteristic structures could provide us useful information on the explosive nucleosynthesis via the observation of elements, which is a unique approach to understand its origin. We here report the discovery of shocked stable Ti, which is produced only at the inner region of exploding stars, in the northeast jet of Cassiopeia A using the 1-Ms deep observation with the Chandra X-ray observatory. The observed Ti coexists with other intermediate-mass elements (e.g. Si, S, Ar, Ca) and Fe at the tip of the X-ray jet structure. We found that its elemental composition is well explained with the production by the incomplete Si burning regime, indicating that the formation process of the jet structure was sub-energetic at the explosion (the peak temperature during the nuclear burning must be $\lesssim$ 5$\times$10$^{9}$ K at most). Thus, we conclude that the energy source that formed the jet structure was not the primary engine for the supernova explosion. Our results are useful to limit the power of the jet-structure formation process, and a weak jet mechanism with low temperature may be needed to explain it., Comment: Accepted for publication in PASJ, 9 pages, 5 figures, 2 tables

Published
2022
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14. On the nature of the anomalous event in 2021 in the dwarf nova SS Cygni and its multi-wavelength transition

Author

Kimura, Mariko, Yamada, Shinya, Nakaniwa, Nozomi, Makita, Yoshihiro, Negoro, Hitoshi, Shidatsu, Megumi, Kato, Taichi, Enoto, Teruaki, Isogai, Keisuke, Mihara, Tatehiro, Akazawa, Hidehiko, Gendreau, Keith C., Hambsch, Franz-Josef, Dubovsky, Pavol A., Kudzej, Igor, Kasai, Kiyoshi, Tordai, Tamás, Pavlenko, Elena, Sosnovskij, Aleksei A., Babina, Julia V., Antonyuk, Oksana I., Itoh, Hiroshi, and Maehara, Hiroyuki

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

SS Cyg has long been recognized as the prototype of a group of dwarf novae that show only outbursts. However, this object has entered a quite anomalous event in 2021, which at first appeared to be standstill, i.e., an almost constant luminosity state, observed in Z Cam-type dwarf novae. This unexpected event gives us a great opportunity to reconsider the nature of standstill in cataclysmic variables. We have observed this anomalous event and its forerunner, a gradual and simultaneous increase in the optical and X-ray flux during quiescence, through many optical telescopes and the X-ray telescopes NICER and NuSTAR. We have not found any amplification of the orbital hump during quiescence before the anomalous event, which suggests that the mass transfer rate did not significantly fluctuate on average. The estimated X-ray flux was not enough to explain the increment of the optical flux during quiescence via X-ray irradiation of the disk and the secondary star. It would be natural to consider that viscosity in the quiescent disk was enhanced before the anomalous event, which increased mass accretion rates in the disk and raised not only the optical flux but also the X-ray flux. We suggest that enhanced viscosity also triggered the standstill-like phenomenon in SS Cyg, which is considered to be a series of small outbursts. The inner part of the disk would always stay in the outburst state and only its outer part would be unstable against the thermal-viscous instability during this phenomenon, which is consistent with the observed optical color variations. This scenario is in line with our X-ray spectral analyses which imply that the X-ray emitting inner accretion flow became hotter than usual and vertically expanded and that it became denser and was cooled down after the onset of the standstill-like state., Comment: Accepted for publication in PASJ. 18 pages, 10 figures, and 2 tables

Published
2021
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17. On the origin of the asymmetry of the ejecta structure and explosion of G350.1$-$0.3

Author

Tsuchioka, Tomoya, Uchiyama, Yasunobu, Higurashi, Ryota, Iwasaki, Hiroyoshi, Otsuka, Shumpei, Yamada, Shinya, and Sato, Toshiki

Subjects
Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract

We present X-ray analysis of the ejecta of supernova remnant G350.1$-$0.3 observed with Chandra and Suzaku, and clarify the ejecta's kinematics over a decade and obtain a new observational clue to understanding the origin of the asymmetric explosion. Two images of Chandra X-ray Observatory taken in 2009 and 2018 are analyzed in several methods, and enable us to measure the velocities in the plane of the sky. A maximum velocity is 4640$\pm$290 km s$^{-1}$ (0.218$\pm$0.014 arcsec yr$^{-1}$) in the eastern region in the remnant. These findings trigger us to scrutinize the Doppler effects in the spectra of the thermal emission, and the velocities in the line-of-sight direction are estimated to be a thousand km s$^{-1}$. The results are confirmed by analyzing the spectra of Suzaku. Combining the proper motions and line-of-sight velocities, the ejecta's three-dimensional velocities are $\sim$3000-5000 km s$^{-1}$. The center of the explosion is more stringently constrained by finding the optimal time to reproduce the observed spatial expansion. Our findings that the age of the SNR is estimated at most to be 655 years, and the CCO is observed as a point source object against the SNR strengthen the 'hydrodynamical kick' hypothesis on the origin of the remnant., Comment: ApJ accepted. 12 pages, 6 figures

Published
2021
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18. Structural insight using anomalous XRD into Mn2CoAl Heusler alloy films grown by magnetron sputtering, IBAS and MBE techniques

Author

Tajiri, Hiroo, Kumara, Loku Singgappulige Rosantha, Sakuraba, Yuya, Chen, Zixi, Wang, Jian, Zhou, Weinan, Varun, Kushwaha, Ueda, Kenji, Yamada, Shinya, Hamaya, Kohei, and Hono, Kazuhiro

Subjects
Condensed Matter - Materials Science
Abstract

Inverse Heusler alloy Mn2CoAl thin films, known as a spin-gapless semiconductor (SGS), grown by three different methods: ultra-high vacuum magnetron spattering, Ar-ion beam assisted sputtering, and molecular beam epitaxy, are investigated by comparing their electric transport properties, microstructures and atomic-level structures. Of the samples, the Mn2CoAl thin film grown by MBE consists of Mn- and Co-rich phases, the structures of which are determined to be the L21B-type and disordered L21-type, respectively, according to anomalous XRD analysis. None of them forms the XA-type structure expected for SGS Heusler alloy, although they all show SGS characteristics. We suggest, to validate SGS characteristics, it is necessary to extract not only magnetic and electric transport properties but also information about microstructures and atomic-scale structures of the films including defects such as atomic swap.

Published
2020

22. High-sensitive XANES analysis at Ce L2-edge for Ce in bauxites using transition-edge sensors: Implications for Ti-rich geological samples

Author

Li, Wenshuai, Yamada, Shinya, Hashimoto, Tadashi, Okumura, Takuma, Hayakawa, Ryota, Nitta, Kiyofumi, Sekizawa, Oki, Suga, Hiroki, Uruga, Tomoya, Ichinohe, Yuto, Sato, Toshiki, Toyama, Yuichi, Noda, Hirofumi, Isobe, Tadaaki, Takatori, Sayuri, Hiraki, Takahiro, Tatsuno, Hideyuki, Kominato, Nao, Ito, Masaki, Sakai, Yusuke, Omamiuda, Hajime, Yamaguchi, Akiko, Yomogida, Takumi, Miura, Hikaru, Nagasawa, Makoto, Okada, Shinji, and Takahashi, Yoshio

Published
2023
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24. Detection of polarized gamma-ray emission from the Crab nebula with Hitomi Soft Gamma-ray Detector

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier, Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stephane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Lukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shin'ichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, and Uchida, Yuusuke

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present the results from the Hitomi Soft Gamma-ray Detector (SGD) observation of the Crab nebula. The main part of SGD is a Compton camera, which in addition to being a spectrometer, is capable of measuring polarization of gamma-ray photons. The Crab nebula is one of the brightest X-ray / gamma-ray sources on the sky, and, the only source from which polarized X-ray photons have been detected. SGD observed the Crab nebula during the initial test observation phase of Hitomi. We performed the data analysis of the SGD observation, the SGD background estimation and the SGD Monte Carlo simulations, and, successfully detected polarized gamma-ray emission from the Crab nebula with only about 5 ks exposure time. The obtained polarization fraction of the phase-integrated Crab emission (sum of pulsar and nebula emissions) is (22.1 $\pm$ 10.6)% and, the polarization angle is 110.7$^o$ + 13.2 / $-$13.0$^o$ in the energy range of 60--160 keV (The errors correspond to the 1 sigma deviation). The confidence level of the polarization detection was 99.3%. The polarization angle measured by SGD is about one sigma deviation with the projected spin axis of the pulsar, 124.0$^o$ $\pm$0.1$^o$., Comment: 19 pages, 18 figures, 6 tables. Accepted for publication in PASJ

Published
2018
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25. Hitomi X-ray Observation of the Pulsar Wind Nebula G21.5$-$0.9

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier, Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stéphane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sato, Toshiki, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Łukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shin'ichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, Nakaniwa, Nozomu, Murakami, Hiroaki, and Guest, Benson

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present results from the Hitomi X-ray observation of a young composite-type supernova remnant (SNR) G21.5$-$0.9, whose emission is dominated by the pulsar wind nebula (PWN) contribution. The X-ray spectra in the 0.8-80 keV range obtained with the Soft X-ray Spectrometer (SXS), Soft X-ray Imager (SXI) and Hard X-ray Imager (HXI) show a significant break in the continuum as previously found with the NuSTAR observation. After taking into account all known emissions from the SNR other than the PWN itself, we find that the Hitomi spectra can be fitted with a broken power law with photon indices of $\Gamma_1=1.74\pm0.02$ and $\Gamma_2=2.14\pm0.01$ below and above the break at $7.1\pm0.3$ keV, which is significantly lower than the NuSTAR result ($\sim9.0$ keV). The spectral break cannot be reproduced by time-dependent particle injection one-zone spectral energy distribution models, which strongly indicates that a more complex emission model is needed, as suggested by recent theoretical models. We also search for narrow emission or absorption lines with the SXS, and perform a timing analysis of PSR J1833$-$1034 with the HXI and SGD. No significant pulsation is found from the pulsar. However, unexpectedly, narrow absorption line features are detected in the SXS data at 4.2345 keV and 9.296 keV with a significance of 3.65 $\sigma$. While the origin of these features is not understood, their mere detection opens up a new field of research and was only possible with the high resolution, sensitivity and ability to measure extended sources provided by an X-ray microcalorimeter., Comment: 16 pages, 8 figures, 4 tables. Accepted for publication in PASJ

Published
2018
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26. Temperature Structure in the Perseus Cluster Core Observed with Hitomi

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furukawa, Maki, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Kato, Yuichi, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier, Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stéphane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Łukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shiníchiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shiníchiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, and Zoghbi, Abderahmen

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The present paper investigates the temperature structure of the X-ray emitting plasma in the core of the Perseus cluster using the 1.8--20.0 keV data obtained with the Soft X-ray Spectrometer (SXS) onboard the Hitomi Observatory. A series of four observations were carried out, with a total effective exposure time of 338 ks and covering a central region $\sim7'$ in diameter. The SXS was operated with an energy resolution of $\sim$5 eV (full width at half maximum) at 5.9 keV. Not only fine structures of K-shell lines in He-like ions but also transitions from higher principal quantum numbers are clearly resolved from Si through Fe. This enables us to perform temperature diagnostics using the line ratios of Si, S, Ar, Ca, and Fe, and to provide the first direct measurement of the excitation temperature and ionization temperature in the Perseus cluster. The observed spectrum is roughly reproduced by a single temperature thermal plasma model in collisional ionization equilibrium, but detailed line ratio diagnostics reveal slight deviations from this approximation. In particular, the data exhibit an apparent trend of increasing ionization temperature with increasing atomic mass, as well as small differences between the ionization and excitation temperatures for Fe, the only element for which both temperatures can be measured. The best-fit two-temperature models suggest a combination of 3 and 5 keV gas, which is consistent with the idea that the observed small deviations from a single temperature approximation are due to the effects of projection of the known radial temperature gradient in the cluster core along the line of sight. Comparison with the Chandra/ACIS and the XMM-Newton/RGS results on the other hand suggests that additional lower-temperature components are present in the ICM but not detectable by Hitomi SXS given its 1.8--20 keV energy band., Comment: 29 pages, 19 figures, 9 tables. Accepted for publication in PASJ

Published
2017
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27. Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hell, Natalie, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier, Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stéphane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Łukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shin'ichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, and Raassen, A. J. J.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The Hitomi SXS spectrum of the Perseus cluster, with $\sim$5 eV resolution in the 2-9 keV band, offers an unprecedented benchmark of the atomic modeling and database for hot collisional plasmas. It reveals both successes and challenges of the current atomic codes. The latest versions of AtomDB/APEC (3.0.8), SPEX (3.03.00), and CHIANTI (8.0) all provide reasonable fits to the broad-band spectrum, and are in close agreement on best-fit temperature, emission measure, and abundances of a few elements such as Ni. For the Fe abundance, the APEC and SPEX measurements differ by 16%, which is 17 times higher than the statistical uncertainty. This is mostly attributed to the differences in adopted collisional excitation and dielectronic recombination rates of the strongest emission lines. We further investigate and compare the sensitivity of the derived physical parameters to the astrophysical source modeling and instrumental effects. The Hitomi results show that an accurate atomic code is as important as the astrophysical modeling and instrumental calibration aspects. Substantial updates of atomic databases and targeted laboratory measurements are needed to get the current codes ready for the data from the next Hitomi-level mission., Comment: 46 pages, 25 figures, 11 tables. Accepted for publication in PASJ

Published
2017
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28. Hitomi Observations of the LMC SNR N132D: Highly Redshifted X-ray Emission from Iron Ejecta

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier, Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stéphane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sato, Toshiki, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Łukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shin'ichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, and Zoghbi, Abderahmen

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present Hitomi observations of N132D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only 3.7 ks, the Soft X-ray Spectrometer (SXS) easily detects the line complexes of highly ionized S K and Fe K with 16-17 counts in each. The Fe feature is measured for the first time at high spectral resolution. Based on the plausible assumption that the Fe K emission is dominated by He-like ions, we find that the material responsible for this Fe emission is highly redshifted at ~800 km/s compared to the local LMC interstellar medium (ISM), with a 90% credible interval of 50-1500 km/s if a weakly informative prior is placed on possible line broadening. This indicates (1) that the Fe emission arises from the supernova ejecta, and (2) that these ejecta are highly asymmetric, since no blue-shifted component is found. The S K velocity is consistent with the local LMC ISM, and is likely from swept-up ISM material. These results are consistent with spatial mapping that shows the He-like Fe concentrated in the interior of the remnant and the S tracing the outer shell. The results also show that even with a very small number of counts, direct velocity measurements from Doppler-shifted lines detected in extended objects like supernova remnants are now possible. Thanks to the very low SXS background of ~1 event per spectral resolution element per 100 ks, such results are obtainable during short pointed or slew observations with similar instruments. This highlights the power of high-spectral-resolution imaging observations, and demonstrates the new window that has been opened with Hitomi and will be greatly widened with future missions such as the X-ray Astronomy Recovery Mission (XARM) and Athena., Comment: 18 pages, 15 figures, 1 table. Accepted for publication by PASJ

Published
2017
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37. Glimpse of the highly obscured HMXB IGR J16318-4848 with Hitomi

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier O., Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stéphane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemitsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Łukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shin'ichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, and Nakaniwa, Nozomi

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We report a Hitomi observation of IGR J16318-4848, a high-mass X-ray binary system with an extremely strong absorption of N_H~10^{24} cm^{-2}. Previous X-ray studies revealed that its spectrum is dominated by strong fluorescence lines of Fe as well as continuum emission. For physical and geometrical insight into the nature of the reprocessing material, we utilize the high spectroscopic resolving power of the X-ray microcalorimeter (the soft X-ray spectrometer; SXS) and the wide-band sensitivity by the soft and hard X-ray imager (SXI and HXI) aboard Hitomi. Even though photon counts are limited due to unintended off-axis pointing, the SXS spectrum resolves Fe K{\alpha_1} and K{\alpha_2} lines and puts strong constraints on the line centroid and width. The line width corresponds to the velocity of 160^{+300}_{-70} km s^{-1}. This represents the most accurate, and smallest, width measurement of this line made so far from any X-ray binary, much less than the Doppler broadening and shift expected from speeds which are characteristic of similar systems. Combined with the K-shell edge energy measured by the SXI and HXI spectra, the ionization state of Fe is estimated to be in the range of Fe I--IV. Considering the estimated ionization parameter and the distance between the X-ray source and the absorber, the density and thickness of the materials are estimated. The extraordinarily strong absorption and the absence of a Compton shoulder component is confirmed. These characteristics suggest reprocessing materials which are distributed in a narrow solid angle or scattering primarily with warm free electrons or neutral hydrogen., Comment: 17 pages, 9 figures, 2 tables, accepted for publication in PASJ

Published
2017
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38. Hitomi Observation of Radio Galaxy NGC 1275: The First X-ray Microcalorimeter Spectroscopy of Fe-K{\alpha} Line Emission from an Active Galactic Nucleus

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier O., Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stéphane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemitsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Łukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shin'ichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, and Kawamuro, Taiki

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The origin of the narrow Fe-K{\alpha} fluorescence line at 6.4 keV from active galactic nuclei has long been under debate; some of the possible sites are the outer accretion disk, the broad line region, a molecular torus, or interstellar/intracluster media. In February-March 2016, we performed the first X-ray microcalorimeter spectroscopy with the Soft X-ray Spectrometer (SXS) onboard the Hitomi satellite of the Fanaroff-Riley type I radio galaxy NGC 1275 at the center of the Perseus cluster of galaxies. With the high energy resolution of ~5 eV at 6 keV achieved by Hitomi/SXS, we detected the Fe-K{\alpha} line with ~5.4 {\sigma} significance. The velocity width is constrained to be 500-1600 km s$^{-1}$ (FWHM for Gaussian models) at 90% confidence. The SXS also constrains the continuum level from the NGC 1275 nucleus up to ~20 keV, giving an equivalent width ~20 eV of the 6.4 keV line. Because the velocity width is narrower than that of broad H{\alpha} line of ~2750 km s$^{-1}$, we can exclude a large contribution to the line flux from the accretion disk and the broad line region. Furthermore, we performed pixel map analyses on the Hitomi/SXS data and image analyses on the Chandra archival data, and revealed that the Fe-K{\alpha} line comes from a region within ~1.6 kpc from the NGC 1275 core, where an active galactic nucleus emission dominates, rather than that from intracluster media. Therefore, we suggest that the source of the Fe-K{\alpha} line from NGC 1275 is likely a low-covering fraction molecular torus or a rotating molecular disk which probably extends from a pc to hundreds pc scale in the active galactic nucleus system., Comment: 20 pages, 8 figures, 6 tables, accepted for publication in PASJ

Published
2017
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39. Atmospheric gas dynamics in the Perseus cluster observed with Hitomi

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Canning, Rebecca E. A., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashi, Tasuku, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Shota, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier, Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stéphane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Łukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shin'ichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Keigo, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shin'ichiro, Urry, C. Megan, Ursino, Eugenio, Wang, Qian H. S., Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, and Zoghbi, Abderahmen

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100~kpc of the Perseus cluster using observations obtained with the Hitomi satellite. After correcting for the point spread function of the telescope and using optically thin emission lines, we find that the line-of-sight velocity dispersion of the hot gas is remarkably low and mostly uniform. The velocity dispersion reaches maxima of approximately 200~km~s$^{-1}$ toward the central active galactic nucleus (AGN) and toward the AGN inflated north-western `ghost' bubble. Elsewhere within the observed region, the velocity dispersion appears constant around 100~km~s$^{-1}$. We also detect a velocity gradient with a 100~km~s$^{-1}$ amplitude across the cluster core, consistent with large-scale sloshing of the core gas. If the observed gas motions are isotropic, the kinetic pressure support is less than 10\% of the thermal pressure support in the cluster core. The well-resolved optically thin emission lines have Gaussian shapes, indicating that the turbulent driving scale is likely below 100~kpc, which is consistent with the size of the AGN jet inflated bubbles. We also report the first measurement of the ion temperature in the intracluster medium, which we find to be consistent with the electron temperature. In addition, we present a new measurement of the redshift to the brightest cluster galaxy NGC~1275., Comment: 52 pages, 16 figures, 8 tables, accepted for publication in PASJ

Published
2017
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40. Measurements of resonant scattering in the Perseus cluster core with Hitomi SXS

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Greg V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier O., Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stephane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sato, Toshiki, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Lukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shinichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shinichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, Furukawa, Maki, and Ogorzalek, Anna

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Thanks to its high spectral resolution (~5 eV at 6 keV), the Soft X-ray Spectrometer (SXS) on board Hitomi enables us to measure the detailed structure of spatially resolved emission lines from highly ionized ions in galaxy clusters for the first time. In this series of papers, using the SXS we have measured the velocities of gas motions, metallicities and the multi-temperature structure of the gas in the core of the Perseus cluster. Here, we show that when inferring physical properties from line emissivities in systems like Perseus, the resonant scattering (RS) effect should be taken into account. In the Hitomi waveband, RS mostly affects the FeXXV He$\alpha$ line ($w$) - the strongest line in the spectrum. The flux measured by Hitomi in this line is suppressed by a factor ~1.3 in the inner ~30 kpc, compared to predictions for an optically thin plasma; the suppression decreases with the distance from the center. The $w$ line also appears slightly broader than other lines from the same ion. The observed distortions of the $w$ line flux, shape and distance dependence are all consistent with the expected effect of the resonant scattering in the Perseus core. By measuring the ratio of fluxes in optically thick ($w$) and thin (FeXXV forbidden, He$\beta$, Ly$\alpha$) lines, and comparing these ratios with predictions from Monte Carlo radiative transfer simulations, the velocities of gas motions have been obtained. The results are consistent with the direct measurements of gas velocities from line broadening described elsewhere in this series, although the systematic and statistical uncertainties remain significant. Further improvements in the predictions of line emissivities in plasma models, and deeper observations with future X-ray missions will enable RS measurements to provide powerful constraints on the amplitude and anisotropy of clusters gas motions., Comment: 30 pages, 17 figure, 6 tables, accepted for publication in PASJ

Published
2017
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41. Semi-Analytical Model for Wind-Fed Black Hole High-Mass X-ray Binaries -- State Transition Triggered by Magnetic Fields from the Companion Star --

Author

Yaji, Kentaro, Yamada, Shinya, and Masai, Kuniaki

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We propose a mechanism of state transition in wind-fed black hole binaries (high-mass X-ray binaries) such as Cyg X-1 and LMC X-1. Modeling a line-driven stellar wind from the companion by two-dimensional hydrodynamical calculations, we investigate the processes of wind capture by and accretion onto the black hole. We assume that the wind acceleration is terminated at the He II ionization front because ions responsible for line-driven acceleration are ionized within the front, i.e. He III region. It is found that the mass accretion rate inferred from the luminosity is remarkably smaller than the capture rate. Considering the difference, we construct a model for the state transition based on the accretion flow being controlled by magneto-rotational instability. The outer flow is torus like, and plays an important role to trigger the transition. The model can explain why state transition does occur in Cyg X-1, while not in LMC X-1. Cyg X-1 exhibits a relatively low luminosity, and then the He II ionization front is located and can move between the companion and black hole, depending on its ionizing photon flux. On the other hand, LMC X-1 exhibits too high luminosity for the front to move considerably; the front is too close to the companion atmosphere. The model also predicts that each state of high-soft or low-hard would last fairly long because the luminosity depends weakly on the wind velocity. In the context of the model, the state transition is triggered by a fluctuation of the magnetic field when its amplitude becomes comparable to the field strength in the torus-like outer flow., Comment: Accepted for publication in ApJ, 26 pages, 5 Tables, 5 Figures

Published
2017
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42. Room-temperature spin transport in n-Ge probed by four-terminal nonlocal measurements

Author

Yamada, Michihiro, Tsukahara, Makoto, Fujita, Yuichi, Naito, Takahiro, Yamada, Shinya, Sawano, Kentarou, and Hamaya, Kohei

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We demonsrtate electrical spin injection and detection in $n$-type Ge ($n$-Ge) at room temperature using four-terminal nonlocal spin-valve and Hanle-effect measurements in lateral spin-valve (LSV) devices with Heusler-alloy Schottky tunnel contacts. The spin diffusion length ($\lambda$$_{\rm Ge}$) of the Ge layer used ($n \sim$ 1 $\times$ 10$^{19}$ cm$^{-3}$) at 296 K is estimated to be $\sim$ 0.44 $\pm$ 0.02 $\mu$m. Room-temperature spin signals can be observed reproducibly at the low bias voltage range ($\le$ 0.7 V) for LSVs with relatively low resistance-area product ($RA$) values ($\le$ 1 k$\Omega$$\mu$m$^{2}$). This means that the Schottky tunnel contacts used here are more suitable than ferromagnet/MgO tunnel contacts ($RA \ge$ 100 k$\Omega$$\mu$m$^{2}$) for developing Ge spintronic applications., Comment: 11 pages, 3 figures

Published
2017
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43. Hitomi X-ray studies of Giant Radio Pulses from the Crab pulsar

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Gregory V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Iwai, Masachika, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier O., Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Oshimizu, Kenya, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stéphane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Ł ukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shiníchiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shiníchiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, Terasawa, Toshio, Sekido, Mamoru, Takefuji, Kazuhiro, Kawai, Eiji, Misawa, Hiroaki, Tsuchiya, Fuminori, Yamazaki, Ryo, Kobayashi, Eiji, Kisaka, Shota, and Aoki, Takahiro

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2 -- 300 keV band and the Kashima NICT radio observatory in the 1.4 -- 1.7 GHz band with a net exposure of about 2 ks on 25 March 2016, just before the loss of the Hitomi mission.The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1,000 and 100 GRPs were simultaneously observed at the main and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main or inter-pulse phases.All variations are within the 2 sigma fluctuations of the X-ray fluxes at the pulse peaks, and the 3 sigma upper limits of variations of main- or inter- pulse GRPs are 22\% or 80\% of the peak flux in a 0.20 phase width, respectively, in the 2 -- 300 keV band.The values become 25\% or 110\% for main or inter-pulse GRPs, respectively, when the phase width is restricted into the 0.03 phase.Among the upper limits from the Hitomi satellite, those in the 4.5-10 keV and the 70-300 keV are obtained for the first time, and those in other bands are consistent with previous reports.Numerically, the upper limits of main- and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) $\times 10^{-11}$ erg cm$^{-2}$, respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magnetosphere and the number of photon-emitting particles temporally increases.However, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a $>0.02$\% brightening of the pulse-peak flux under such conditions., Comment: 18 pages, 7 figure, 6 tables, accepted for publication in PASJ

Published
2017
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44. Search for Thermal X-ray Features from the Crab nebula with Hitomi Soft X-ray Spectrometer

Author

Hitomi Collaboration, Aharonian, Felix, Akamatsu, Hiroki, Akimoto, Fumie, Allen, Steven W., Angelini, Lorella, Audard, Marc, Awaki, Hisamitsu, Axelsson, Magnus, Bamba, Aya, Bautz, Marshall W., Blandford, Roger, Brenneman, Laura W., Brown, Greg V., Bulbul, Esra, Cackett, Edward M., Chernyakova, Maria, Chiao, Meng P., Coppi, Paolo S., Costantini, Elisa, de Plaa, Jelle, de Vries, Cor P., Herder, Jan-Willem den, Done, Chris, Dotani, Tadayasu, Ebisawa, Ken, Eckart, Megan E., Enoto, Teruaki, Ezoe, Yuichiro, Fabian, Andrew C., Ferrigno, Carlo, Foster, Adam R., Fujimoto, Ryuichi, Fukazawa, Yasushi, Furuzawa, Akihiro, Galeazzi, Massimiliano, Gallo, Luigi C., Gandhi, Poshak, Giustini, Margherita, Goldwurm, Andrea, Gu, Liyi, Guainazzi, Matteo, Haba, Yoshito, Hagino, Kouichi, Hamaguchi, Kenji, Harrus, Ilana M., Hatsukade, Isamu, Hayashi, Katsuhiro, Hayashi, Takayuki, Hayashida, Kiyoshi, Hiraga, Junko S., Hornschemeier, Ann, Hoshino, Akio, Hughes, John P., Ichinohe, Yuto, Iizuka, Ryo, Inoue, Hajime, Inoue, Yoshiyuki, Ishida, Manabu, Ishikawa, Kumi, Ishisaki, Yoshitaka, Kaastra, Jelle, Kallman, Tim, Kamae, Tsuneyoshi, Kataoka, Jun, Katsuda, Satoru, Kawai, Nobuyuki, Kelley, Richard L., Kilbourne, Caroline A., Kitaguchi, Takao, Kitamoto, Shunji, Kitayama, Tetsu, Kohmura, Takayoshi, Kokubun, Motohide, Koyama, Katsuji, Koyama, Shu, Kretschmar, Peter, Krimm, Hans A., Kubota, Aya, Kunieda, Hideyo, Laurent, Philippe, Lee, Shiu-Hang, Leutenegger, Maurice A., Limousin, Olivier O., Loewenstein, Michael, Long, Knox S., Lumb, David, Madejski, Greg, Maeda, Yoshitomo, Maier, Daniel, Makishima, Kazuo, Markevitch, Maxim, Matsumoto, Hironori, Matsushita, Kyoko, McCammon, Dan, McNamara, Brian R., Mehdipour, Missagh, Miller, Eric D., Miller, Jon M., Mineshige, Shin, Mitsuda, Kazuhisa, Mitsuishi, Ikuyuki, Miyazawa, Takuya, Mizuno, Tsunefumi, Mori, Hideyuki, Mori, Koji, Mukai, Koji, Murakami, Hiroshi, Mushotzky, Richard F., Nakagawa, Takao, Nakajima, Hiroshi, Nakamori, Takeshi, Nakashima, Shinya, Nakazawa, Kazuhiro, Nobukawa, Kumiko K., Nobukawa, Masayoshi, Noda, Hirofumi, Odaka, Hirokazu, Ohashi, Takaya, Ohno, Masanori, Okajima, Takashi, Ota, Naomi, Ozaki, Masanobu, Paerels, Frits, Paltani, Stephane, Petre, Robert, Pinto, Ciro, Porter, Frederick S., Pottschmidt, Katja, Reynolds, Christopher S., Safi-Harb, Samar, Saito, Shinya, Sakai, Kazuhiro, Sasaki, Toru, Sato, Goro, Sato, Kosuke, Sato, Rie, Sato, Toshiki, Sawada, Makoto, Schartel, Norbert, Serlemtsos, Peter J., Seta, Hiromi, Shidatsu, Megumi, Simionescu, Aurora, Smith, Randall K., Soong, Yang, Stawarz, Lukasz, Sugawara, Yasuharu, Sugita, Satoshi, Szymkowiak, Andrew, Tajima, Hiroyasu, Takahashi, Hiromitsu, Takahashi, Tadayuki, Takeda, Shinichiro, Takei, Yoh, Tamagawa, Toru, Tamura, Takayuki, Tanaka, Takaaki, Tanaka, Yasuo, Tanaka, Yasuyuki T., Tashiro, Makoto S., Tawara, Yuzuru, Terada, Yukikatsu, Terashima, Yuichi, Tombesi, Francesco, Tomida, Hiroshi, Tsuboi, Yohko, Tsujimoto, Masahiro, Tsunemi, Hiroshi, Tsuru, Takeshi Go, Uchida, Hiroyuki, Uchiyama, Hideki, Uchiyama, Yasunobu, Ueda, Shutaro, Ueda, Yoshihiro, Uno, Shinichiro, Urry, C. Megan, Ursino, Eugenio, Watanabe, Shin, Werner, Norbert, Wilkins, Dan R., Williams, Brian J., Yamada, Shinya, Yamaguchi, Hiroya, Yamaoka, Kazutaka, Yamasaki, Noriko Y., Yamauchi, Makoto, Yamauchi, Shigeo, Yaqoob, Tahir, Yatsu, Yoichi, Yonetoku, Daisuke, Zhuravleva, Irina, Zoghbi, Abderahmen, Tominaga, Nozomu, and Moriya, Takashi J.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

The Crab nebula originated from a core-collapse supernova (SN) explosion observed in 1054 A.D. When viewed as a supernova remnant (SNR), it has an anomalously low observed ejecta mass and kinetic energy for an Fe-core collapse SN. Intensive searches were made for a massive shell that solves this discrepancy, but none has been detected. An alternative idea is that the SN1054 is an electron-capture (EC) explosion with a lower explosion energy by an order of magnitude than Fe-core collapse SNe. In the X-rays, imaging searches were performed for the plasma emission from the shell in the Crab outskirts to set a stringent upper limit to the X-ray emitting mass. However, the extreme brightness of the source hampers access to its vicinity. We thus employed spectroscopic technique using the X-ray micro-calorimeter onboard the Hitomi satellite. By exploiting its superb energy resolution, we set an upper limit for emission or absorption features from yet undetected thermal plasma in the 2-12 keV range. We also re-evaluated the existing Chandra and XMM-Newton data. By assembling these results, a new upper limit was obtained for the X-ray plasma mass of <~ 1Mo for a wide range of assumed shell radius, size, and plasma temperature both in and out of the collisional equilibrium. To compare with the observation, we further performed hydrodynamic simulations of the Crab SNR for two SN models (Fe-core versus EC) under two SN environments (uniform ISM versus progenitor wind). We found that the observed mass limit can be compatible with both SN models if the SN environment has a low density of <~ 0.03 cm-3 (Fe core) or <~ 0.1 cm-3 (EC) for the uniform density, or a progenitor wind density somewhat less than that provided by a mass loss rate of 10-5 Mo yr-1 at 20 km s-1 for the wind environment., Comment: PASJ in press. Figures are now properly included

Published
2017
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45. Haematopoietic regeneration by HLA‐A*0206‐deficient clones in severe aplastic anaemia without definitive immunosuppressive treatment.

Author

Zaimoku, Yoshitaka, Sakai, Kazuya, Tsuji, Noriaki, Hosomichi, Kazuyoshi, Yamada, Shinya, Tran, Dung Cao, Kobayashi, Miku, Sugiyama, Ayana, Hirayasu, Kouyuki, Mizumaki, Hiroki, Ishiyama, Ken, Hanayama, Rikinari, Tomiyama, Yoshiaki, and Nakao, Shinji

Abstract

Summary: We describe the case of a 74‐year‐old man with severe aplastic anaemia who experienced persistent remission attributed to proliferation of HLA allele‐deficient clones. Despite an initial worsening of pancytopenia with eltrombopag and ciclosporin treatment, gradual trilineage haematopoietic recovery occurred, with blood counts normalizing over 3 years. Flow cytometry and deep nucleotide sequencing revealed that haematopoiesis was primarily supported by several clones with somatic mutations that inactivated antigen presentation via HLA‐A*0206. This suggests that monitoring haematopoietic regeneration by immune escape clones could be an alternative approach for immune aplastic anaemia patients who possess HLA allele‐deficient clones and cannot tolerate standard therapy. [ABSTRACT FROM AUTHOR]

Published
2024
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46. Polarized X-rays correlated with the short-timescale variability of Cygnus X-1.

Author

Ninoyu, Kaito, Uchida, Yuusuke, Yamada, Shinya, Kohmura, Takayoshi, Igarashi, Taichi, Hayakawa, Ryota, and Kawamura, Tenyo

Subjects
BREWSTER'S angle, X-ray binaries, BLACK holes, X-ray imaging, X-rays
Abstract

We systematically investigate the variability of polarized X-rays on a timescale of a few seconds in the low/hard state of the black hole binary Cygnus X-1. The correlation between polarization degrees and angles with X-ray intensity was analyzed using data collected by the Imaging X-ray Polarimetry Explorer (IXPE) in 2022 June. Given that X-ray variability in the low/hard state of Cygnus X-1 is non-periodic, flux peaks were aggregated to suppress statistical fluctuations. We divided the temporal profiles of these aggregated flux peaks into seven time segments and evaluated the polarization for each segment. The results reveal that the polarization degree was 4.6% |$\pm$| 1.2% and 5.3% |$\pm$| 1.2% before and after the peak, respectively, but decreased to 3.4% |$\pm$| 1.1% and 2.7% |$\pm$| 1.1% in the segments including and immediately following the peak. Furthermore, the polarization angle exhibited a slight shift from approximately 30 |$^{\circ }$| to |${\sim} 40^{\circ }$| before and after the peak. These findings suggest that the accretion disk contracts with increasing X-ray luminosity, and the closer proximity of the X-ray emitting gas to the black hole may lead to reduced polarization. [ABSTRACT FROM AUTHOR]

Published
2024
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47. Optimal surveillance interval after piecemeal endoscopic mucosal resection for large colorectal neoplasia: a multicenter randomized controlled trial

Author

Nakajima, Takeshi, Sakamoto, Taku, Hori, Shinichiro, Yamada, Shinya, Ikematsu, Hiroaki, Harada, Keita, Chiu, Han-Mo, Kiriyama, Shinsuke, Michida, Tomoki, Hotta, Kinichi, Sakamoto, Naoto, Abe, Takashi, Chino, Akiko, Fukuzawa, Masakatsu, Kobayashi, Nozomu, Fukase, Kazutoshi, Matsuda, Takahisa, Murakami, Yoshitaka, Ishikawa, Hideki, and Saito, Yutaka

Published
2022
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50. Procalcitonin, brain natriuretic peptide and albumin as markers to predict prognosis in hospitalized older Japanese patients with a risk of infection

Author

Higashikawa, Toshihiro, primary, Ito, Toru, additional, Ito, Tomohiko, additional, Mizuno, Takuro, additional, Ishigami, Keiichirou, additional, Kuroki, Kengo, additional, Maekawa, Naoto, additional, Usuda, Daisuke, additional, Yoshida, Michiteru, additional, Morita, Takuro, additional, Hamada, Kazu, additional, Yano, Hiroshi, additional, Takeshima, Kento, additional, Haraguchi, Takatoshi, additional, Yamada, Shinya, additional, Yamada, Sohsuke, additional, Ushimoto, Tomoyuki, additional, Sangen, Ryusho, additional, Izumida, Toshihide, additional, Kiyosawa, Jun, additional, Ono, Taisuke, additional, Iguchi, Masaharu, additional, Wato, Yukihiro, additional, Nakahashi, Takeshi, additional, Kasamaki, Yuji, additional, Fukuda, Akihiro, additional, Kanda, Tsugiyasu, additional, Morimoto, Shigeto, additional, and Okuro, Masashi, additional

Published
2024
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