Frequency dependence of tidal q

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

For studies of tidal evolution, values of the key parameter Q, and its frequency dependence, are often derived from estimates of internal energy dissipation when a satellite, planet, or star is physically distorted. Such estimates come from geophysical or astrophysical modeling, from seismic data, from ad hoc assumptions, or from constraints based on current spins and orbits. In a standard procedure, Q values are used to determine the lag in the response to each Fourier component of the tidal potential. The separate components are then co-added. The basis for this procedure is the analogy of the damped, driven, harmonic oscillator. However, this lag-and-add procedure would not be justifiable even for such a simple system, except for a very specific dependence of Q on frequency. There is no reason to expect the lag-and-add procedure to be relevant for a complex system, because the relationship between dissipation rates and tidal lags is unknown. This widely applied type of model is a reasonable approximation only if the decomposed tidal potential involves a narrow range of frequencies, and thus may only be appropriate for analyses to low order in orbital eccentricity and inclination.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume698
Issue number1 PART 2
DOIs
StatePublished - 2009

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frequency dependence
energy dissipation
eccentricity
dissipation
seismic data
time lag
planet
modeling
estimates
complex systems
internal energy
harmonic oscillators
inclination
planets
astrophysics
orbits
stars
orbitals
rate
parameter

Keywords

  • Celestial mechanics
  • Planetary systems
  • Planets and satellites: general

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Frequency dependence of tidal q. / Greenberg, Richard J.

In: Astrophysical Journal, Vol. 698, No. 1 PART 2, 2009.

Research output: Contribution to journalArticle

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