Astronomy and Astrophysics – Astrophysics
Scientific paper
1995-09-21
Astronomy and Astrophysics
Astrophysics
AASTeX, 25 pages, plus 4 figures in compressed postscript. Revised only to wrap lines longer than 80 characters
Scientific paper
10.1086/177565
We calculate the damping of quadrupole f and low order g modes (primary modes) by nonlinear coupling to other modes of the star. This damping is orders of magnitude more rapid than direct radiative damping when the primary amplitude is large, as in tidal capture. Primary modes destabilize high degree g-modes of half their frequency (daughter modes) by 3-mode coupling in radiative zones. In sunlike stars, the growth time $\equiv\eta^{-1}\approx 4 E_{0,42}^{-1/2}$ days, where $E_{0,42}$ is the initial energy of the primary mode in units of $10^{42}~$erg, and of order $10^{10}E_{0,42}^{5/4}$ daughters are unstable. The growth rate is approximately equal to the angular frequency of the primary mode times its dimensionless radial amplitude, $\delta R/R_*\approx 0.002E_{0,42}^{1/2}$. Although the daughter modes are limited by their own nonlinearities, collectively they absorb most of the primary mode's energy after a time $\sim 10\eta^{-1}$ provided $E_{0}> 10^{40}~\mbox{erg}$. In fact nonlinear mode interaction may be the dominant damping process if $E_0\gtrsim 10^{37}~\mbox{erg}$. Our results have application to tidally captured main sequence globular cluster stars of mass $\ge 0.5 M_{\sun}$; the tidal energy is dissipated in the radiative core of the star in about a month, which is less than the initial orbital period.
Goodman Jeremy
Kumar Pawan
No associations
LandOfFree
Nonlinear Damping of Oscillations in Tidal-Capture Binaries does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Nonlinear Damping of Oscillations in Tidal-Capture Binaries, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonlinear Damping of Oscillations in Tidal-Capture Binaries will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-703936