### Abstract

We study the nature of non-axisymmetric dynamical instabilities in differentially rotating stars with both linear eigenmode analysis and hydrodynamic simulations in Newtonian gravity. We especially investigate the following three types of instability; the one-armed spiral instability, the low T/|W| bar instability, and the high T/|W| bar instability, where T is the rotational kinetic energy and W is the gravitational potential energy. The nature of the dynamical instabilities is clarified by using a canonical angular momentum as a diagnostic. We find that the one-armed spiral and the low T/|W| bar instabilities occur around the corotation radius, and they grow through the inflow of canonical angular momentum around the corotation radius. The result is a clear contrast to that of a classical dynamical bar instability in high T/|W|. We also discuss the feature of gravitational waves generated from these three types of instability.

Original language | English |
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Title of host publication | AIP Conference Proceedings |

Pages | 728-735 |

Number of pages | 8 |

Volume | 861 |

DOIs | |

Publication status | Published - 2006 |

Externally published | Yes |

Event | Albert Einstein Century International Conference - Paris Duration: 2005 Jul 18 → 2005 Jul 22 |

### Other

Other | Albert Einstein Century International Conference |
---|---|

City | Paris |

Period | 05/7/18 → 05/7/22 |

### Fingerprint

### Keywords

- Gravitational waves
- Hydrodynamics
- Instabilities
- Stars: Evolution
- Stars: Oscillation
- Stars: Rotation

### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*AIP Conference Proceedings*(Vol. 861, pp. 728-735) https://doi.org/10.1063/1.2399650

**Low T/|W| dynamical instabilities in differentially rotating stars : Diagnosis with canonical angular momentum.** / Saijo, Motoyuki; Yoshida, Shin'Ichirou.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*AIP Conference Proceedings.*vol. 861, pp. 728-735, Albert Einstein Century International Conference, Paris, 05/7/18. https://doi.org/10.1063/1.2399650

}

TY - GEN

T1 - Low T/|W| dynamical instabilities in differentially rotating stars

T2 - Diagnosis with canonical angular momentum

AU - Saijo, Motoyuki

AU - Yoshida, Shin'Ichirou

PY - 2006

Y1 - 2006

N2 - We study the nature of non-axisymmetric dynamical instabilities in differentially rotating stars with both linear eigenmode analysis and hydrodynamic simulations in Newtonian gravity. We especially investigate the following three types of instability; the one-armed spiral instability, the low T/|W| bar instability, and the high T/|W| bar instability, where T is the rotational kinetic energy and W is the gravitational potential energy. The nature of the dynamical instabilities is clarified by using a canonical angular momentum as a diagnostic. We find that the one-armed spiral and the low T/|W| bar instabilities occur around the corotation radius, and they grow through the inflow of canonical angular momentum around the corotation radius. The result is a clear contrast to that of a classical dynamical bar instability in high T/|W|. We also discuss the feature of gravitational waves generated from these three types of instability.

AB - We study the nature of non-axisymmetric dynamical instabilities in differentially rotating stars with both linear eigenmode analysis and hydrodynamic simulations in Newtonian gravity. We especially investigate the following three types of instability; the one-armed spiral instability, the low T/|W| bar instability, and the high T/|W| bar instability, where T is the rotational kinetic energy and W is the gravitational potential energy. The nature of the dynamical instabilities is clarified by using a canonical angular momentum as a diagnostic. We find that the one-armed spiral and the low T/|W| bar instabilities occur around the corotation radius, and they grow through the inflow of canonical angular momentum around the corotation radius. The result is a clear contrast to that of a classical dynamical bar instability in high T/|W|. We also discuss the feature of gravitational waves generated from these three types of instability.

KW - Gravitational waves

KW - Hydrodynamics

KW - Instabilities

KW - Stars: Evolution

KW - Stars: Oscillation

KW - Stars: Rotation

UR - http://www.scopus.com/inward/record.url?scp=53849124568&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=53849124568&partnerID=8YFLogxK

U2 - 10.1063/1.2399650

DO - 10.1063/1.2399650

M3 - Conference contribution

AN - SCOPUS:53849124568

SN - 9780735403598

VL - 861

SP - 728

EP - 735

BT - AIP Conference Proceedings

ER -