Curriculum Vitaes
Profile Information
- Affiliation
- Associate professor, Institute of Space and Astronautical Science, Japan Aerospace Exploration AgencyAssociate professor, Space and Astronautical Science, Graduate Institute for Advanced Studies, The Graduate University for Advanced Studies
- Degree
- Ph. D.(Mar, 1998, Kyoto University)master's degree(Mar, 1995, Kyoto University)
- Researcher number
- 80342624
- ORCID ID
https://orcid.org/0000-0002-9099-5755- J-GLOBAL ID
- 202001011170717781
- researchmap Member ID
- R000011919
Research Areas
2Research History
7-
Apr, 2026 - Present
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Apr, 2007 - Mar, 2026
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Oct, 2003 - Mar, 2007
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Jul, 2001 - Sep, 2003
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Apr, 2001 - Jun, 2001
Education
3-
Apr, 1995 - Mar, 1998
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Apr, 1993 - Apr, 1995
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Apr, 1989 - Mar, 1993
Papers
279-
Journal of Astronomical Telescopes, Instruments, and Systems, 12(02), May 22, 2026
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The Astrophysical Journal, 1002(2) 222-222, May 8, 2026Abstract We present updated hard X-ray polarization measurements of the Crab pulsar and nebula obtained with the balloon-borne polarimeter XL-Calibur in the ∼19–64 keV energy range. During the flight, intermittent failure of the Global Positioning System (GPS) receiver resulted in poorly constrained timing for ∼38% of the Crab dataset. By implementing a new phase recovery method that reconstructs timing during extended GPS-off intervals, phase tag data are recovered for ∼95% of the GPS-off dataset, increasing the precision of the phase-resolved analysis. Phase information for the data is recovered by using the Crab pulsar, with its 33 ms period, as an external timing source. Using a Markov Chain Monte Carlo framework to jointly fit phase offsets and frequency derivatives, sufficient phase accuracy is achieved across multiple periods without GPS for a phase-resolved analysis. This enables inclusion of nearly the full dataset in the polarization study. The polarization degree of the nebular emission is found to be (27.7 ± 4.9)% at a polarization angle of 127 2 ± 5 1, confirming previous XL-Calibur results and remaining aligned with the Crab’s spin axis, consistent with synchrotron emission from the inner nebula. Phase-resolved measurements show that the off-pulse and bridge intervals exhibit a strong polarization, while the pulsar peaks, although weakly constrained, remain in agreement with the softer-energy trends of IXPE. These findings reinforce a scenario in which hard X-ray emission arises primarily in the nebular torus and wind regions. The successful recovery of precise phase tagging from GPS-off data demonstrates the capacity to use the pulsar as an external clock even in the case of sparsely populated data.
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Publications of the Astronomical Society of Japan, Apr 9, 2026Abstract We report the presence of a highly ionized absorber in the transient, eclipsing low-mass X-ray binary AX J1745.6-2901, observed from 2024 February 26–29 with XRISM’s Resolve and Xtend instruments. During a soft/high state without dips, Resolve’s high spectral resolution ($E/\Delta E \sim 1000$, full width at half-maximum) revealed narrow velocity widths ($\sigma \sim 110~{\rm km~s^{-1 } }$) for Fe xxvi and Ni xxviii lines, even with low photon statistics. These widths are consistent with binary orbital motion. The observed modest blueshift velocity (${\sim }160~{\rm km~s^{-1 } }$) indicates that the absorber is located sufficiently far from the neutron star (${>}10^9$ cm), so that gravitational redshift effects are not dominant. On the other hand, broad-band spectral analysis using a photoionized plasma model applied to the Xtend data constrains the absorber to lie within a radius of ${\lesssim }10^{9.5}$ cm, as inferred from the upper limits of the best-fitting ionization parameter ($\log \xi \sim 4.4$) and the large column density (${\sim }1.6\times 10^{24}~{\rm cm^{-2 } }$). At this distance, the observed outward velocity of the absorber is about an order of magnitude smaller than the escape velocity from the neutron star.
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Journal of Astronomical Telescopes, Instruments, and Systems, 12(01), Mar 26, 2026
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Journal of Astronomical Telescopes, Instruments, and Systems, 12(01), Mar 14, 2026
Misc.
102-
日本天文学会年会講演予稿集, 2025, 2025
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日本天文学会年会講演予稿集, 2024, 2024
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日本物理学会講演概要集(CD-ROM), 79(1), 2024
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日本物理学会講演概要集(CD-ROM), 79(1), 2024
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日本物理学会講演概要集(CD-ROM), 79(2), 2024
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日本物理学会講演概要集(CD-ROM), 78(1), 2023
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日本物理学会講演概要集(CD-ROM), 78(2), 2023
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日本物理学会講演概要集(CD-ROM), 78(2), 2023
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日本物理学会講演概要集(CD-ROM), 78(2), 2023
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大気球シンポジウム: 2022年度 = Balloon Symposium: 2022, Nov, 2022大気球シンポジウム 2022年度(2022年11月7-8日. ハイブリッド開催(JAXA相模原キャンパス& オンライン)) Balloon Symposium 2022 (November 7-8, 2022. Hybrid(in-person & online) Conference (Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan 著者人数: 87名 資料番号: SA6000177030 レポート番号: isas22-sbs-030
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日本物理学会講演概要集(CD-ROM), 77(1), 2022
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日本物理学会講演概要集(CD-ROM), 77(2), 2022
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日本物理学会講演概要集(CD-ROM), 77(1), 2022
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日本物理学会講演概要集(CD-ROM), 77(2), 2022
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大気球シンポジウム: 2021年度 = Balloon Symposium: 2021, Nov, 2021大気球シンポジウム 2021年度(2021年11月1-2日. オンライン開催) Balloon Symposium 2021 (November 1-2, 2021. Online Meeting) 著者人数: 93名PDF再処理の為、2023年3月24日に差替 資料番号: SA6000166020 レポート番号: isas21-sbs-020
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日本物理学会講演概要集(CD-ROM), 76(1), 2021
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日本物理学会講演概要集(CD-ROM), 76(2), 2021
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日本物理学会講演概要集(CD-ROM), 76(2), 2021
Presentations
8-
Optics & Photonics Japan 2023, Nov 29, 2023 Invited
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44th COSPAR Scientific Assembly, 2022
Teaching Experience
7-
Sep, 2025 - Mar, 2026宇宙理学概論(オムニパス) (総合研究大学院大学)
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Sep, 2023 - Mar, 2024
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Apr, 2021 - Mar, 2022Space Science Review (The Graduate University for Advanced Studies)
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Oct, 2019 - Mar, 2020Space Science Review (The Graduate University for Advanced Studies)
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Oct, 2009 - Mar, 2010Applied Physics (Chuo University)
Professional Memberships
4-
Jul, 1998 - Present
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Mar, 1998 - Present
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Jan, 1997 - Present
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Aug, 1993 - Present
Research Projects
12-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2023 - Mar, 2027
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Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2022 - Mar, 2025
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Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2022 - Mar, 2025
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Japan Society for the Promotion of Science, Apr, 2020 - Mar, 2023
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科学研究費助成事業 挑戦的研究(萌芽), 日本学術振興会, Jun, 2019 - Mar, 2022