研究者業績
基本情報
- 所属
- 国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 宇宙物理学研究系 教授総合研究大学院大学 先端学術院 宇宙科学コース 教授東京工業大学 理学院 特定教授
- 学位
- 博士（理学）(東京大学)修士(東京大学)
- 研究者番号
- 20280555
- ORCID ID
https://orcid.org/0000-0002-2374-7073- J-GLOBAL ID
- 200901095989600566
- researchmap会員ID
- 1000363020
X線マイクロカロリメータを用いた極低温精密X線分光装置の開発に取り組み，2023年9月打ち上げのXRISM衛星に搭載されたResolve観測装置として実現しました．
研究指導のテーマとしては，(1) XRISM衛星による精密X線分光観測データを解析し，銀河団ガスの運動を調べて，宇宙の大規模構造形成過程の理解を深める，(2) 宇宙マイクロ波背景放射の偏光観測を目指すLiteBIRD衛星を見据えた実験的研究を行なう等．特定の自然現象について理解を深めると同時に，複雑な自然現象の背景にある物理法則に至る過程を，実験・解析手法とともにしっかりと身につけてもらいたいと考えています．
研究キーワード
6経歴
8-
2024年6月 - 現在
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2024年3月 - 現在
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2023年6月 - 2024年6月
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2023年6月 - 現在
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2008年4月 - 2023年5月
学歴
4-
1991年4月 - 1995年3月
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- 1995年
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1987年4月 - 1991年3月
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- 1991年
委員歴
2-
2009年4月 - 2011年3月
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2009年 - 2010年
受賞
2-
2010年
論文
164-
Publications of the Astronomical Society of Japan 2024年10月10日Abstract We present an initial analysis of the X-Ray Imaging and Spectroscopy Mission (XRISM) first-light observation of the supernova remnant (SNR) N 132D in the Large Magellanic Cloud. The Resolve microcalorimeter has obtained the first high-resolution spectrum in the 1.6–10 keV band, which contains K-shell emission lines of Si, S, Ar, Ca, and Fe. We find that the Si and S lines are relatively narrow, with a broadening represented by a Gaussian-like velocity dispersion of $\sigma _v \sim 450$ km s$^{-1}$. However, the Fe He$\alpha$ lines are substantially broadened with $\sigma _v \sim 1670$ km s$^{-1}$. This broadening can be explained by a combination of the thermal Doppler effect due to the high ion temperature and the kinematic Doppler effect due to the SNR expansion. Assuming that the Fe He$\alpha$ emission originates predominantly from the supernova ejecta, we estimate the reverse shock velocity at the time when the bulk of the Fe ejecta were shock heated to be $-1000 \lesssim V_{\rm rs}$ (km s$^{-1}$) $\lesssim 3300$ (in the observer frame). We also find that Fe Ly$\alpha$ emission is redshifted with a bulk velocity of $\sim 890$ km s$^{-1}$, substantially larger than the radial velocity of the local interstellar medium surrounding N 132D. These results demonstrate that high-resolution X-ray spectroscopy is capable of providing constraints on the evolutionary stage, geometry, and velocity distribution of SNRs.
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The Astrophysical Journal Letters 973(1) L25-L25 2024年9月1日Abstract We present an analysis of the first two XRISM/Resolve spectra of the well-known Seyfert-1.5 active galactic nucleus (AGN) in NGC 4151, obtained in 2023 December. Our work focuses on the nature of the narrow Fe K α emission line at 6.4 keV, the strongest and most common X-ray line observed in AGN. The total line is found to consist of three components. Even the narrowest component of the line is resolved with evident Fe K α,1 (6.404 keV) and K α,2 (6.391 keV) contributions in a 2:1 flux ratio, fully consistent with neutral gas with negligible bulk velocity. Subject to the limitations of our models, the narrowest and intermediate-width components are consistent with emission from optically thin gas, suggesting that they arise in a disk atmosphere and/or wind. Modeling the three line components in terms of Keplerian broadening, they are readily associated with (1) the inner wall of the “torus,” (2) the innermost optical “broad-line region” (or “X-ray BLR”), and (3) a region with a radius of r ≃ 100 GM/c 2 that may signal a warp in the accretion disk. Viable alternative explanations of the broadest component include a fast-wind component and/or scattering; however, we find evidence of variability in the narrow Fe K α line complex on timescales consistent with small radii. The best-fit models are statistically superior to simple Voigt functions, but when fit with Voigt profiles the time-averaged lines are consistent with a projected velocity broadening of FWHM . Overall, the resolution and sensitivity of XRISM show that the narrow Fe K line in AGN is an effective probe of all key parts of the accretion flow, as it is currently understood. We discuss the implications of these findings for our understanding of AGN accretion, future studies with XRISM, and X-ray-based black hole mass measurements.
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Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray 53-53 2024年8月22日
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Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray 55-55 2024年8月22日
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Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray 52-52 2024年8月21日
MISC
131-
PASJ : publications of the Astronomical Society of Japan 59(1 SPEC. ISS.) S77-S112 2007年
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PASJ : publications of the Astronomical Society of Japan 59(1 SPEC. ISS.) S339-S349 2007年
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Progress of Theoretical Physics Supplement (169) 322-325 2007年We present the in-flight performance of the X-ray telescopes (XRTs) onboard Suzaku. The imaging capability is significantly improved over the ASCA XRT, which had half-power diameters of 3'.6, to 1'.8-2'.3 for all four XRT-I modules. Contemporaneous fits of a power law to all the XIS spectra of the Crab Nebula taken at the two standard observing positions (XIS/HXD-default positions) gives a flux consistent with that obtained by Toor & Seward (1974) to within〜2%. The pre-collimator on the top of each XRT module successfully reduces the intensity of the stray light from the 20' and 50'-off directions down to the level of pre-flight expectations. We also present the thermal wobbling of the satellite. The wobbling causes the alignment error between the XRT-XIS system and the attitude and orbit control system. The wobbling of the alignment is as large as〜1arcmin. In the currently processed data, the absolute coordinate also has systematic uncertainty of up to〜1arcmin.
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PASJ : publications of the Astronomical Society of Japan 59(1 SPEC. ISS.) S269-S282 2007年
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スターリングサイクルシンポジウム講演論文集 2006(10) 73-74 2006年10月19日Cryogenic cooling is useful to most detectors in astronomical and atmospheric observation for improving the sensitivity and reducing the background noise. Recently cryocoolers are often adopted as cooling devices. This paper describes a single stage Stirling cryocooler. It is designed, manufactured and tested for space borne mission. The typical cooling power is 2W at 80K with 50W input. The cooler on the X-ray telescope satellite "Suzaku" was launched July 2005. It is operating over 1 year without any trouble. On the other hand, a cooler achieved 50,000 hour operation in the lifetime test on the ground. Same type coolers will be launched on the lunar explorer and the Venus orbiter of Japan
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日本物理学会講演概要集 61(2) 72-72 2006年8月18日
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日本物理学会講演概要集 61(1) 87-87 2006年3月4日
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Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray, Pts 1 and 2 6266(No.) G2660-G2660 2006年We present our proposal for a small X-ray mission DIOS (Diffuse Intergalactic Oxygen Surveyor), consisting of a 4-stage X-ray telescope and an array of TES microcalorimeters, cooled with mechanical coolers, with a total weight of about 400 kg. The mission will perform survey observations of warm-hot intergalactic medium using OVII and OVIII emission lines, with the energy coverage up to 1.5 keV. The wide field of view of about 50' diameter, superior energy resolution close to 2 eV FWHM, and very low background will together enable us a wide range of science for diffuse X-ray sources. We briefly describe the design of the satellite, performance of the subsystems and the expected results.
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AIP Conference Proceedings 774 379-382 2005年6月13日The XRS microcalorimeter will be launched in 2005 as part of the Astro-E2 mission. It will cover the energy band from 0.3 to 10 keV with a nearly constant energy resolution of 6.0 eV and a peak effective area of 200 cm 2 at 1.5 keV. The XRS will provide unprecedented throughput and resolving power, particularly at high energies. Detailed spectral features in the Fe K region will be resolved for the first time, providing access to spectroscopic diagnostics for a wide range of astrophysical objects. In this presentation we will describe the XRS instrument, details of its spectral performance, and how it compares to the current high-resolution instruments on the Chandra and XMM-Newton observatories. © 2005 American Institute of Physics.
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日本物理学会講演概要集 60(1) 209-209 2005年3月4日
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Journal of the Korean Physical Society 45(SUPPL.) 2004年Approximately 30 to 50 percent of the total baryons in the present universe is supposed to take the form of wa arm/hot intergalactic medium (WHIM) whose X-ray continuum emission is very weak. In order to carry out a direct and homogeneous survey of elusive cosmic missing baryons, we propose a dedicated soft-X-ray mission, DIOS (Diffuse Intergalactic Oxygen Surveyor). The unprecedented energy resolution (∼ 2eV) of the XSA (X-ray Spectrometer Array) on-board DIOS enables us to identify WHIM with gas temperatures T = 106-7K and overdensity δ= 10-100 located at z < 0.3 through emission lines of OVII and OVIII. DIOS, which will hopefully be launched in several years time, promises to open a new window of detection and characterization of cosmic missing baryons and to provide yet another important and complementary tool to trace the large-scale structure of the universe.
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PASJ : publications of the Astronomical Society of Japan 56(5) L29-L34-L34 2004年
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NANOTECH 2003, VOL 1 1 436-439 2003年An x-ray microcalorimeter is a promising x-ray spectrometer for its extremely good energy resolution and its good detecting efficiency. We are developing an x-ray microcalorimeter for high energy resolution x-ray imaging application. The energy resolution of 43eV(FWHM) at 5.9keV is obtained with our x-ray microcalorimeter. The intrinsic performance of our x-ray microcalorimeter was estimated to be 10.4eV(FWHM) at 5.9keV. This value is more than 10 times better than that of the 2 WORKING PRINCIPLES conventional x-ray CCD.
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BOSTON TRANSDUCERS'03: DIGEST OF TECHNICAL PAPERS, VOLS 1 AND 2 1108-1111 2003年An x-ray microcalorimeter is a noble x-ray spectrometer that can be used for photon counting with a high energy resolution comparable to the gratings. A 2x2 x-ray microcalorimeter array was fabricated and tested. Due to the purpose of imaging application, we have applied so-called 'mushroom-shaped' x-ray microabsorber fabricated using two-step exposure and electrodeposition process. The energy resolution of 180eV(FWHM) at 5.9keV was obtained with the first prototype of the x-ray microcalorimeter array using Sri microabsorber. By using Bi absorber, it is,estimated that the energy resolution can be improved up to 4.5eV.
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低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity 67 185-185 2002年10月30日
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低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity 67 184-184 2002年10月30日
共同研究・競争的資金等の研究課題
20-
日本学術振興会 科学研究費助成事業 基盤研究(C) 2023年4月 - 2026年3月
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日本学術振興会 科学研究費助成事業 新学術領域研究(研究領域提案型) 2019年4月 - 2021年3月
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日本学術振興会 科学研究費助成事業 基盤研究(A) 2013年4月 - 2017年3月
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日本学術振興会 科学研究費助成事業 基盤研究(B) 2011年4月 - 2014年3月
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科研費 挑戦的萌芽研究 2008年4月 - 2011年3月
