パルサーからの重力波の探索

• Project/Area Number: 15K05070
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Osaka City University (2017-2019); The University of Tokyo (2015-2016)
• Principal Investigator: 伊藤 洋介 大阪市立大学, 大学院理学研究科, 准教授 (60443983)
• Project Period (FY): 2015-04-01 – 2021-03-31
• Project Status: Granted (Fiscal Year 2019)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2019: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2018: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2017: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2015: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 重力波 / パルサー / 中性子星 / 一般相対性理論 / データ解析 / 重力波天文学 / KAGRA

Outline of Annual Research Achievements

本研究はパルサーからの重力波の探索手法の開発と実際の解析を目的としている。パルサーからの重力波は。単独パルサーからも連星パルサーからもいまだ検出されていない、極めてチャレンジングな課題であり、現時点まで多くの試行がなされている。
パルサーからの重力波が検出されると、パルサーの状態方程式の硬さについての制限、クラストの存在の証明、r-modeの存在証明と内部温度進化についての制限、また温度進化モデルとの比較による内部状態の研究が進むと考えられる。低質量X線連星からの重力波が検出された場合、長年謎であった降着円盤と中性子星との相互作用についての問題について知見が得られると考えられる。
本研究課題では独立成分解析を援用して雑音を低減する手法を提案し、日本の重力波検出器KAGRAの初期試験運転によるデータ iKAGRA データを利用してその有効性を示した。また、瞬間的結合と線型性を仮定した独立成分解析が重力波データ解析の文脈では Wiener filter と同一であることを数学的に示した。この結果はすでに論文に出版している。
パルサーからの重力波の振幅は極めて微弱であるため、その重力波検出のためには、米国に建設された LIGO 重力波検出器プロジェクト、ヨーロッパの Virgo プロジェクトとの共同研究が必須である。 私 KAGRA プロジェクトの連続波解析チームリーダーとして昨年より LIGO-Virgo 共同研究体と会合を持ち、以前我々が開発した信号弁別手法を提案するなど、今後の共同研究のための実績と経験を積み重ねているところである。また、X線連星からの重力波の検出において必要なX線位相情報 の獲得のため、NICER group日本メンバーとも連絡を取っている。

Current Status of Research Progress

3: Progress in research has been slightly delayed.

Reason

COVID-19のため、最終年度3月に予定していた米国での研究発表・会合が令和２年度秋以降に延期となっている。

Strategy for Future Research Activity

LIGO-Virgo共同研究体との共同研究を進めるため、現在もおこなっている遠隔会議への参加をより密にし、(1) 以前我々が提案した信号弁別方法を洗練し、(2) LIGO-Virgo 共同研究体がまだおこなっていない研究ターゲットへの参画を狙い、(3) 新しい探索手法を研究開発することによって、パルサーからの重力波の検出を現実のものとする。

Research Products

• [Int'l Joint Research] KISTI/NIMS/UNIST(韓国)
• [Int'l Joint Research] Tamkang University/National Tsing Hua University/Academia Sinica(台湾)
• [Int'l Joint Research] LAPP(フランス)
• [Int'l Joint Research] WIPM/Peking University/Beijing Normal University(中国)
• [Int'l Joint Research] California Institute of Technology/University of Notre Dame/University of Florida(米国)
• [Int'l Joint Research]
• [Journal Article] Application of the independent component analysis to the iKAGRA data (2020)
  • Author(s): KAGRA Collaboration
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2020
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An arm length stabilization system for KAGRA and future gravitational-wave detectors (2020)
  • Author(s): Akutsu T, et al. (KAGRA Collaboration)
  • Journal Title: Classical and Quantum Gravity Volume: 37 Pages: 035004-035004
  • DOI: 10.1088/1361-6382/ab5c95
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Dark matter signals on a laser interferometer (2020)
  • Author(s): Tsuchida Satoshi、Kanda Nobuyuki、Itoh Yousuke、Mori Masaki
  • Journal Title: Physical Review D Volume: 101 Pages: 023005-023005
  • DOI: 10.1103/physrevd.101.023005
  • Peer Reviewed
• [Journal Article] First cryogenic test operation of underground km-scale gravitational-wave observatory KAGRA (2019)
  • Author(s): Akutsu T, et al. (KAGRA Collaboration)
  • Journal Title: Classical Quantum Gravity Volume: 36 Pages: 16-16
  • DOI: 10.1088/1361-6382/ab28a9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Vibration isolation system with a compact damping system for power recycling mirrors of KAGRA. (2019)
  • Author(s): KAGRA Collaboration
  • Journal Title: Classical and Quantum Gravity Volume: 36 Pages: 095015-095015
  • DOI: 10.1088/1361-6382/ab0fcb
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KAGRA: 2.5 Generation Interferometric Gravitational Wave Detector (2019)
  • Author(s): KAGRA collaboration
  • Journal Title: Nature Astronomy Volume: 3 Pages: 35-35
  • DOI: 10.1038/s41550-018-0658-y
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO, Advanced Virgo and KAGRA (2018)
  • Author(s): B. P. Abbott et al.
  • Journal Title: Living Reviews in Relativity Volume: 21 Pages: 1-120
  • DOI: 10.1007/s41114-018-0012-9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Construction of KAGRA : an underground gravitational-wave observatory (2018)
  • Author(s): M Ando, Y Aso, R Flaminio, T Kajita, S Kawamura, N Kimura, K Kuroda, F Matsushima, N Mio, O Miyakawa, S Miyoki, Y Moriwaki, M Ohashi, K Somiya, T Suzuki, T Tomaru, T Uchiyama and KAGRA Collaboration, et al.
  • Journal Title: Progress of Theoretical Physics and Experiments Volume: 2018 Pages: 01-18
  • DOI: 10.1093/ptep/ptx180
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The status of KAGRA underground cryogenic gravitational wave telescope (2017)
  • Author(s): KAGRA Collaboration
  • Journal Title: Proceedings for XV International Conference on Topics in Astroparticle and Underground Physics (TAUP2017), Sudbury, July 24-28, 2017 Volume: 1 Pages: 1-1
  • Int'l Joint Research
• [Journal Article] Toward the detection of gravitational waves under non-Gaussian noises II. Independent component analysis (2017)
  • Author(s): Soichiro MORISAKI, Jun’ichi YOKOYAMA, Kazunari EDA, Yousuke ITOH
  • Journal Title: Proc. Jpn. Acad., Ser. B Volume: 92 Issue: 8 Pages: 336-345
  • DOI: 10.2183/pjab.92.336
  • NAID: 130005420971
  • ISSN: 0386-2208, 1349-2896
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Ground-based low-frequency gravitational-wave detector with multiple outputs (2017)
  • Author(s): Ayaka Shoda, Yuya Kuwahara, Masaki Ando, Kazunari Eda, Kodai Tejima, Yoichi Aso, and Yousuke Itoh
  • Journal Title: Physical Review D Volume: 95 Pages: 082004-082004
  • DOI: 10.1103/physrevd.95.082004
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] "Pre-DECIGO can get the smoking gun to decide the astrophysical or cosmological origin of GW150914-like binary black holes" (2016)
  • Author(s): Nakamura, Takashi; Ando, Masaki; Kinugawa, Tomoya; et al.
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 9 Pages: 930-930
  • DOI: 10.1093/ptep/ptw127
  • NAID: 120005973373
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Characterization of non-Gaussianity in gravitational wave detector noise (2016)
  • Author(s): Takahiro Yamamoto, Kazuhiro Hayama, Shuhei Mano, Yousuke Itoh, and Nobuyuki Kanda
  • Journal Title: Physical Review D Volume: 93 Pages: 082005-082005
  • DOI: 10.1103/physrevd.93.082005
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] All-sky coherent search for continuous gravitational waves in 6-7 Hz band with a torsion-bar antenna (2016)
  • Author(s): Kazunari Eda, Ayaka Shoda, Yuya Kuwahara, Yousuke Itoh, Masaki Ando
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 1 Pages: 1-8
  • DOI: 10.1093/ptep/ptv179
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Determination of mass of an isolated neutron star using continuous gravitational waves with two frequency modes: an effect of a misalignment angle (2016)
  • Author(s): Kazunari Eda, Kenji Ono, Youskue Itoh
  • Journal Title: Proceedings of the 11th Amaldi Conference Volume: In press
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] New estimation method for mass of an isolated neutron star using gravitational waves (2015)
  • Author(s): K.Ono, K.Eda, and Y.Itoh
  • Journal Title: Physical Review D Volume: 91 Pages: 084032-084032
  • DOI: 10.1103/physrevd.91.084032
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Status of KAGRA (2019)
  • Author(s): Yousuke Itoh
  • Organizer: The 29th workshop on General Relativity and Gravitation in Japan
  • Int'l Joint Research / Invited
• [Presentation] Application of the independent component analysis to the iKAGRA data (2019)
  • Author(s): Yousuke Itoh
  • Organizer: New Innovative Area Workshop 2019 Early Summer Osaka City University, Osaka, 2019 June 29
  • Int'l Joint Research
• [Presentation] Continuous GW search in B01 (2017)
  • Author(s): Yousuke Itoh
  • Organizer: New Innovative area “GW-Genesis” Kick-off Workshop @Kyoto, 2017 Sep. 22-23
• [Presentation] Some of GW sources and physics potentials - Interests in 500 ~ kHz GW- (2017)
  • Author(s): Yousuke Itoh
  • Organizer: 3rd KAGRA International Workshop@Academia Sinica, 2017/05/21-22
  • Int'l Joint Research
• [Presentation] GW Physics and Astronomy (2017)
  • Author(s): Yousuke Itoh
  • Organizer: 12th Particle Physics Phenomenology Workshop, National Chiao Tung University, 2017/05/16-19
  • Int'l Joint Research
• [Presentation] 大型低温重力波望遠鏡 KAGRA: 全体 報告 (2017)
  • Author(s): 伊藤洋介
  • Organizer: 日本天文学会2017年秋季年会 9/11-13 (9/12,13:36-13:48), 北海道大学
• [Presentation] Search for continuous gravitational waves from pulsars (2017)
  • Author(s): Yousuke Itoh
  • Organizer: “GW Astronomy”, Kyoto, 24-26 August 2017
• [Presentation] 独立成分分析を用いた重力波実験における非ガウス雑音の除去 (2016)
  • Author(s): 森崎宗一郎、横山順一、枝和成、伊藤洋介
  • Organizer: 日本物理学会２０１６年秋季大会
  • Place of Presentation: 宮崎大学 (宮崎県・宮崎市）
  • Year and Date: 2016-09-21
• [Presentation] iKAGRA データを用いた既知パルサーからの連続重力波探査 (2016)
  • Author(s): 枝和成, KAGRA Collaboration
  • Organizer: 日本物理学会２０１６年秋季大会
  • Place of Presentation: 宮崎大学 (宮崎県・宮崎市）
  • Year and Date: 2016-09-21
• [Presentation] A chi-squared discriminator for continuous gravitational wave detection in all-sky search (2016)
  • Author(s): Kazunari Eda and Youuske Itoh
  • Organizer: The First International Meeting on KAGRA
  • Place of Presentation: Daejon (Korea)
  • Year and Date: 2016-06-23
  • Int'l Joint Research
• [Presentation] A chi-squared veto for semi-coherent F-statistic search in continuous gravitational waves (2016)
  • Author(s): Kazunari Eda and Youuske Itoh
  • Organizer: Gravitational Wave Physics and Astronomy Workshop
  • Place of Presentation: Hyannis (USA)
  • Year and Date: 2016-06-15
  • Int'l Joint Research
• [Presentation] GW150914 の発見とKAGRA におけるデータ解析の現状、展望 (2016)
  • Author(s): 伊藤洋介
  • Organizer: 第１３回原子・分子・光科学（AMO）討論会
  • Place of Presentation: 理化学研究所（埼玉県・和光市）
  • Year and Date: 2016-06-03
  • Invited
• [Presentation] 重力波で探る中性子星 (2015)
  • Author(s): 伊藤 洋介
  • Organizer: 中性子星の観測と理論: 研究活性化ワークショップ
  • Place of Presentation: 京都大学（京都府、京都市）
  • Year and Date: 2015-12-21
• [Presentation] Search for continuous gravitational wave from neutron stars (2015)
  • Author(s): Yousuke Itoh
  • Organizer: Joint symposium by three innovative areas
  • Place of Presentation: 東北大学 (宮城県、仙台市)
  • Year and Date: 2015-07-24
• [Presentation] Development of KAGRA Algorithmic Library (KAGALI) (2015)
  • Author(s): K. Oohara, K. Ueno, H. Yuzurihara, Yosuke Itoh, and 31 authors
  • Organizer: The 14th Marcel Grossmann Meeting (MG14)
  • Place of Presentation: ローマ（イタリア）
  • Year and Date: 2015-07-12
  • Int'l Joint Research
• [Book] 相対論と宇宙の事典 (2020)
  • Author(s): 安東正樹ほか（伊藤洋介 含む）
  • Total Pages: 432
  • Publisher: 朝倉書店
  • ISBN: 9784254131284