On the Asymmetry of Solar Acoustic Line Profiles

Details On the Asymmetry of Solar Acoustic Line Profiles On the Asymmetry of Solar Acoustic Line Profiles

Mar 1998

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998apj...496..527r&link_type=abstract

Astrophysical Journal v.496, p.527

Astronomy and Astrophysics

Astronomy

29

Line: Profiles, Sun: Oscillations

Scientific paper

We study a simplified model of solar acoustic oscillations and show how asymmetries in spectral lines depend both on the acoustic source depth, as previously recognized, and on the acoustic source type. We provide a unified description of modal line asymmetries and high-frequency pseudo-mode locations, suggesting an inversion on power spectra minima to determine source properties and a correction to Lorentzian line shapes based upon the relative locations of spectral peaks and valleys. We also consider nonadiabatic effects due to Newtonian cooling and demonstrate that these do not lead to notable differences between velocity and intensity power spectral line shapes. We argue more generally that it is unlikely that any nonadiabatic effect can be responsible for the observed differences. Finally, we discuss the importance of both multiplicative and additive background power to the spectra and show how additive noise can reduce the apparent line asymmetry of a mode. We note that information on solar convective motions can be potentially extracted from three components of the acoustic power spectra: the additive background yielding information on the spectrum of nonoscillatory motions at the height of observation, the multiplicative background reflecting the source spectrum, and the power minima providing the source depth and physical nature. For stochastically excited linear waves only the first of these contributes significantly to spectral differences between observed variables.

Affiliated with

Also associated with

No associations

Rating

On the Asymmetry of Solar Acoustic Line Profiles 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 On the Asymmetry of Solar Acoustic Line Profiles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Asymmetry of Solar Acoustic Line Profiles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1657302