Portal de Periódicos da CAPES

Excitation of neutron star normal modes during binary inspiral

1994; IOP Publishing; Volume: 426; Linguagem: Inglês

10.1086/174105

1538-4357

Andreas Reisenegger, Peter Goldreich,

Geophysics and Gravity Measurements

view Abstract Citations (93) References (19) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Excitation of Neutron Star Normal Modes during Binary Inspiral Reisenegger, Andreas ; Goldreich, Peter Abstract As a compact binary inspirals due to the emission of gravitational waves, its orbital period decreases continuously down to approximately 1 ms, its value at coalescence. During the last part of the inspiral, the two stars are close together, and their tidal interactions become strong. Neutron stars have many normal modes (core g-modes, crustal discontinuity modes, shear modes, etc.) whose periods lie in the range (approximately several ms) swept by the orbital period. Some of these modes are resonantly excited by the tidal force. The amount of energy a mode absorbs is proportional to the square of the overlap integral between its displacement field and the tidal force field. For all modes of interest, this overlap is poor, resulting in relatively weak excitation. For the best case, the absorbed energy is only a small fraction (approximately 10-6) of the orbital energy, so the orbital phase shift is too weak to be detected by observations of the gravitational wave signal emitted by the inspiraling binary. However, with displacement amplitudes of excited quadrupole modes ranging up to 0.5% of the stellar radius, the possibility of a detectable electromagnetic signature cannot be dismissed. Both the periods of the modes and the energy they absorb depend quite strongly on the internal structure of the star. Their observation could shed light on the correct high-density equation of state. Publication: The Astrophysical Journal Pub Date: May 1994 DOI: 10.1086/174105 Bibcode: 1994ApJ...426..688R Keywords: Binary Stars; Excitation; Gravitational Waves; Neutron Stars; Stellar Orbits; Amplitudes; Equations Of State; Phase Shift; Quadrupoles; Spectral Signatures; Stellar Physics; Stellar Structure; Variations; Astrophysics; GRAVITATION; STARS: BINARIES: CLOSE; STARS: NEUTRON; STARS: OSCILLATIONS full text sources ADS |