WHAT CAUSES p-MODE ASYMMETRY REVERSAL?
نویسندگان
چکیده
The solar acoustic p-mode line profiles are asymmetric. Velocity spectra have more power on the low-frequency sides, whereas intensity profiles show the opposite sense of asymmetry. Numerical simulations of the upper convection zone have resonant p-modes with the same asymmetries and asymmetry reversal as the observed modes. The temperature and velocity power spectra at optical depth τcont = 1 have the opposite asymmetry as is observed for the intensity and velocity spectra. At a fixed geometrical depth, corresponding to < τcont >= 1, however, the temperature and velocity spectra have the same asymmetry. This indicates that the asymmetry reversal is produced by radiative transfer effects and not by correlated noise. Subject headings: convection — methods: numerical — radiative transfer — Sun: oscillations
منابع مشابه
ar X iv : a st ro - p h / 02 05 14 1 v 1 9 M ay 2 00 2 To appear in ApJ What Causes P - mode Asymmetry Reversal ?
The solar acoustic p-mode line profiles are asymmetric. Velocity spectra have more power on the low-frequency sides, whereas intensity profiles show the opposite sense of asymmetry. Numerical simulations of the upper convection zone have resonant p-modes with the same asymmetries and asymmetry reversal as the observed modes. The temperature and velocity power spectra at optical depth τ cont = 1...
متن کاملLine asymmetry of solar p-modes: Reversal of asymmetry in intensity power spectra
The sense of line asymmetry of solar p-modes in the intensity power spectra is observed to be opposite of that seen in the velocity power spectra. Theoretical calculations provide a good understanding and fit to the observed velocity power spectra whereas the reverse sense of asymmetry in the intensity power spectrum has been poorly understood. We show that when turbulent eddies arrive at the t...
متن کاملar X iv : a st ro - p h / 96 10 25 4 v 1 3 0 O ct 1 99 6 Asymmetries of Solar p - mode Line Profiles
Recent observations indicate that solar p-mode line profiles are not exactly Lorentzian, but rather exhibit varying amounts of asymmetry about their respective peaks. We analyze p-mode line asymmetry using both a simplified one-dimensional model and a more realistic solar model. We find that the amount of asymmetry exhibited by a given mode depends on the location of the sources exciting the mo...
متن کاملAsymmetric reversal modes in ferromagnetic/antiferromagnetic multilayers.
Experimentally an asymmetry of the reversal modes has been found in certain exchange bias systems. From a numerical investigation of the domain state model evidence is gained that this effect depends on the angle between the easy axis of the antiferromagnet and the applied magnetic field. Depending on this angle the ferromagnet reverses either symmetrically, e.g., by a coherent rotation on both...
متن کامل2 6 M ay 2 00 7 Symmetries of the ratchet current
Recent advances in nonequilibrium statistical mechanics shed new light on the ratchet effect. The ratchet motion can thus be understood in terms of symmetry (breaking) considerations. We introduce an additional symmetry operation besides time-reversal, that switches between two modes of operation. That mode-reversal combined with time-reversal decomposes the nonequilibrium action so as to clari...
متن کامل