Computer Science
Scientific paper
Dec 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008coast.157..356o&link_type=abstract
Communications in Asteroseismology, Vol.157, p. 356
Computer Science
1
Scientific paper
Among the methods used to investigate the effect of rotation on oscillation frequencies of stellar pressure modes, we consider here perturbation techniques and direct numerical integrations of a two dimensional eigenvalue system - nonperturbative approach. Knowing the accuracy of asteroseismic data provided by CoRoT, the issue is to determine whether it is sustainable to take the effect of rotation on stellar oscillations into account with a perturbative approach, or if we should adopt a nonperturbative method that could be much heavier numerically. The aim of this study is to determine the limits - in terms of rotational angular velocity - of a perturbative approach to model the effects of rotation on both structure and oscillation frequencies. Until now, 2D nonperturbative oscillation code has only been developed for polytropic models but not for realistic models of stars. Thus, we have used a polytropic model to compare the results of a 2D nonperturbative oscillation code provided by D. Reese, and a 1D second order perturbative one. For models whose angular velocity of rotation is that of a δ Scuti type star, say 70 - 145 km s-1 , we find a relative frequency difference between the results of the two codes of 0.03% to 0.17%. Considering an optimistic evaluation of uncertainties on CoRoT frequency splittings mesurements - 0.2 µHz about 500 µHz: relative frequency uncertainty 0.04% - we can already conclude that the perturbative method seems to be acceptable for a 2 solar radius star up to about 100 km s-1 but not further. We expect to push the validity limits of this method a little further taking into account additional corrections such as near-degeneracy coupling - work in progress.
No associations
LandOfFree
Validity domain of a perturbative approach for rot. effects on asteroseismic data 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 Validity domain of a perturbative approach for rot. effects on asteroseismic data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Validity domain of a perturbative approach for rot. effects on asteroseismic data will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-965100