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Evolution of star clusters: from star fromation to gravitational wave emission

Research Project

Project/Area Number 19F19317
Research Category

Grant-in-Aid for JSPS Fellows

Allocation TypeSingle-year Grants
Section外国
Review Section Basic Section 16010:Astronomy-related
Research InstitutionThe University of Tokyo

Principal Investigator

藤井 通子  東京大学, 大学院理学系研究科(理学部), 准教授 (90722330)

Co-Investigator(Kenkyū-buntansha) WANG LONG  東京大学, 理学(系)研究科(研究院), 外国人特別研究員
Wang Long  東京大学, 理学(系)研究科(研究院), 外国人特別研究員
Project Period (FY) 2019-11-08 – 2022-03-31
Project Status Completed (Fiscal Year 2021)
Budget Amount *help
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2021: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2020: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2019: ¥600,000 (Direct Cost: ¥600,000)
Keywords星団 / ブラックホール連星 / N体シミュレーション / star cluster / N-body simulation / binary black hole / gravitational wave / numerical simulations / stellar dynamics / star formation / binary stars / stellar multiplicity
Outline of Research at the Start

Gravitational waves (GW) detection is a new channel of observing black hole (BH) and neutron star (NS), which are difficult to detect by using traditional telescopes. Thus, GW provides a unique way to study BHs/NSs. In this research, a series of large N-body simulations of star clusters, where GW progenitors can efficiently form, will be carried out to study correlations between star formation, stellar dynamics and properties of GW progenitors. Using the result, we make predictions of the characteristics of GW events, such as the mass of the progenitors, event rate and more detailed features.

Outline of Annual Research Achievements

We have developed a new N-body code, PeTar. Comparing the previous fastest code, the new code has several significant advantages: 1, For more than 100,000 stars, the performance of the code is much faster; 2. Using the slow-down algorithmic regularization method, it can handle 100 % binary fraction; 3. It has a well-designed user interface with rich data analysis tools; 4. It is modularized, and thus, including new functions from other codes.
By including updated stellar evolution code, BSE, we have investigated how the top-heavy IMF affects the event rate of GWs, we found that GCs with a top-heavy IMF is not efficient to produce GW mergers due to a low density after a strong expansion because of massive stellar wind mass loss. We also found the mass ratio distribution of BBHs is also different from that of GCs with the canonical IMF.
We have also carried out the first N-body models of intermediate massive star clusters with up to 100% binary fractions. We found that only massive primordial binaries can affect the long-term evolution of star clusters, but the effect is weak. This suggests that we can ignore low-mass binaries in the numerical modelling of GCs if we only care about the GW events.
By including PeTar in the hydrodynamical code, ASURA+BRIDGE, we studied how the OB binary affect the star formation of Orion nebular star clusters (ONC). We found the ejection of OB stars significantly affect the HII region in star-forming region, and thus, the binary dynamics affect the formation of multiple stellar population in ONC.

Research Progress Status

令和3年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和3年度が最終年度であるため、記入しない。

Report

(3 results)
  • 2021 Annual Research Report
  • 2020 Annual Research Report
  • 2019 Annual Research Report
  • Research Products

    (32 results)

All 2021 2020 2019 Other

All Int'l Joint Research (11 results) Journal Article (10 results) (of which Int'l Joint Research: 4 results,  Peer Reviewed: 10 results,  Open Access: 3 results) Presentation (9 results) (of which Int'l Joint Research: 3 results) Remarks (2 results)

  • [Int'l Joint Research] University of Padova(イタリア)

    • Related Report
      2021 Annual Research Report
  • [Int'l Joint Research] Nicolaus Copernicus Astronomical Center(ポーランド)

    • Related Report
      2021 Annual Research Report
  • [Int'l Joint Research] The SPODYR Group/Charles University/GRANTECAN(チェコ)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] MPA/Astronomisches Rechen-Institut/Heidelberg University(ドイツ)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] NCAC(ポーランド)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] Columbia University/Princeton University(米国)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] Nicolaus Copernicus Astronomical Center(ポーランド)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Lund University(スウェーデン)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Leiden University(オランダ)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Bonn Univesity/MPA, Garching(ドイツ)

    • Related Report
      2019 Annual Research Report
  • [Int'l Joint Research] Observatory of Astronomy in Padova(イタリア)

    • Related Report
      2019 Annual Research Report
  • [Journal Article] SIRIUS project. III. Star-by-star simulations of star cluster formation using a direct <i> <b>N</b> </i>-body integrator with stellar feedback2021

    • Author(s)
      Fujii Michiko S、Saitoh Takayuki R、Hirai Yutaka、Wang Long
    • Journal Title

      Publications of the Astronomical Society of Japan

      Volume: 73 Issue: 4 Pages: 1074-1099

    • DOI

      10.1093/pasj/psab061

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] SIRIUS project. II. A new tree-direct hybrid code for smoothed particle hydrodynamics/<i>N</i>-body simulations of star clusters2021

    • Author(s)
      Fujii Michiko S、Saitoh Takayuki R、Wang Long、Hirai Yutaka
    • Journal Title

      Publications of the Astronomical Society of Japan

      Volume: 73 Issue: 4 Pages: 1057-1073

    • DOI

      10.1093/pasj/psab037

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Impact of initial mass functions on the dynamical channel of gravitational wave sources2021

    • Author(s)
      Wang Long、Fujii Michiko S、Tanikawa Ataru
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: 504 Issue: 4 Pages: 5778-5787

    • DOI

      10.1093/mnras/stab1157

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed
  • [Journal Article] A slow-down time-transformed symplectic integrator for solving the few-body problem2020

    • Author(s)
      Wang Long、Nitadori Keigo、Makino Junichiro
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: 493 Issue: 3 Pages: 3398-3411

    • DOI

      10.1093/mnras/staa480

    • Related Report
      2020 Annual Research Report 2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] petar: a high-performance N-body code for modelling massive collisional stellar systems2020

    • Author(s)
      Wang Long、Iwasawa Masaki、Nitadori Keigo、Makino Junichiro
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: 497 Issue: 1 Pages: 536-555

    • DOI

      10.1093/mnras/staa1915

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Very high redshift quasars and the rapid emergence of super-massive black holes2020

    • Author(s)
      Kroupa Pavel、Subr Ladislav、Jerabkova Tereza、Wang Long
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: 498 Pages: 5652-5683

    • DOI

      10.1093/mnras/staa2276

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Intermediate mass black hole formation in compact young massive star clusters2020

    • Author(s)
      Rizzuto Francesco Paolo、Naab Thorsten、Spurzem Rainer、Giersz Mirek、Ostriker J P、Stone N C、Wang Long、Berczik Peter、Rampp M
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: 501 Issue: 4 Pages: 5257-5273

    • DOI

      10.1093/mnras/staa3634

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] The survival of star clusters with black hole subsystems2020

    • Author(s)
      Wang Long
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: 491 Pages: 2413-2423

    • DOI

      10.1093/mnras/stz3179

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed
  • [Journal Article] Accelerated FDPS: Algorithms to use accelerators with FDPS2020

    • Author(s)
      Iwasawa Masaki、Namekata Daisuke、Nitadori Keigo、Nomura Kentaro、Wang Long、Tsubouchi Miyuki、Makino Junichiro
    • Journal Title

      Publications of the Astronomical Society of Japan

      Volume: 72 Issue: 1 Pages: 13-13

    • DOI

      10.1093/pasj/psz133

    • NAID

      120006840182

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] The possible role of stellar mergers for the formation of multiple stellar populations in globular clusters2019

    • Author(s)
      Wang Long、Kroupa Pavel、Takahashi Koh、Jerabkova Tereza
    • Journal Title

      Monthly Notices of the Royal Astronomical Society

      Volume: 491 Issue: 1 Pages: 440-454

    • DOI

      10.1093/mnras/stz3033

    • Related Report
      2019 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Presentation] The impact of IMFs on the dynamical channels of gravitational wave sources2021

    • Author(s)
      Long Wang
    • Organizer
      CHALLENGES AND INNOVATIONS IN COMPUTATIONAL ASTROPHYSICS III
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] The implementation of PeTar in AMUSE2021

    • Author(s)
      Long Wang
    • Organizer
      MODEST-21a: AMUSE
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Impact of initial mass functions on the dynamical channel of gravitational wave sources2021

    • Author(s)
      Long Wang
    • Organizer
      GW Genesis: new science A03 workshop
    • Related Report
      2021 Annual Research Report
  • [Presentation] Impact of initial mass functions on the dynamical channel of gravitational wave sources2021

    • Author(s)
      Long Wang
    • Organizer
      ASJ 2021 Autumn Annual Meeting
    • Related Report
      2021 Annual Research Report
  • [Presentation] The 3 million-star simulations of globular clusters using Fugaku computer2021

    • Author(s)
      Long Wang
    • Organizer
      ASJ 2021 Spring Annual Meeting
    • Related Report
      2020 Annual Research Report
  • [Presentation] The impact of IMFs on the dynamical channels of gravitational wave sources,2021

    • Author(s)
      Long Wang
    • Organizer
      GW Genesis: Group A Winter Camp 2021
    • Related Report
      2020 Annual Research Report
  • [Presentation] The connection between dynamical evolution of star clusters, IMFs and BH mergers2020

    • Author(s)
      Long Wang
    • Organizer
      GW Genesis:First Stars & First Galaxies 2020
    • Related Report
      2020 Annual Research Report
  • [Presentation] PeTar a high-performance N-body code for modelling massive collisional stellar systems2020

    • Author(s)
      Long Wang
    • Organizer
      IAU CB1 CHALLENGES AND INNOVATIONS IN COMPUTATIONAL ASTROPHYSICS - II
    • Related Report
      2020 Annual Research Report
    • Int'l Joint Research
  • [Presentation] The connection between stellar dynamics and BH mergers2020

    • Author(s)
      Long Wang
    • Organizer
      Gravitational Wave Physics and Astronomy: Genesis
    • Related Report
      2019 Annual Research Report
  • [Remarks] SIRIUS Project

    • URL

      https://sites.google.com/g.ecc.u-tokyo.ac.jp/sirius-project/

    • Related Report
      2021 Annual Research Report
  • [Remarks] GitHub

    • URL

      https://github.com/lwang-astro

    • Related Report
      2020 Annual Research Report

URL: 

Published: 2019-11-29   Modified: 2024-03-26  

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