Inferred acoustic rates of solar p modes from several helioseismic instruments

Acoustic rates of excitation of solar p modes can be estimated from observations in order to place constraints on the modelling of the excitation process and the layers where it occurs in the star. For several reasons (including a poor signal to noise ratio and mode overlap), this estimation is difficult. In this work, we use three completely independent datasets to obtain robust estimates in the solar case for � = 1 modes. We also show that the height in the solar atmosphere where the modes are observed must be taken into account. Our three sets of results are shown to be consistent, particularly in the lower part of the p-mode spectrum (from 1.8 mHz to 2.8 mHz). At higher frequencies, the agreement is not as good, because of a larger dispersion of the measurements and also because of some systematic differences which might be due to observation height estimation or to a systematic influence of the noise.

[1]  T. Appourchaux.  On Maximum Likelihood Estimation of averaged power spectra , 2003 .

[2]  USA,et al.  Numerical 3D constraints on convective eddy time-correlations: Consequences for stochastic excitation of solar p modes , 2003, astro-ph/0304457.

[3]  R. Stein,et al.  WHAT CAUSES p-MODE ASYMMETRY REVERSAL? , 2002, astro-ph/0205141.

[4]  W. Chaplin,et al.  On the measurement bias of low-l solar p-mode excitation parameters: The impact of a ground-based window function , 2003 .

[5]  U. Heiter,et al.  New grids of ATLAS9 atmospheres I: Influence of convection treatments on model structure and on observable quantities , 2002, astro-ph/0206156.

[6]  J. Christensen-Dalsgaard,et al.  Changes in convective properties over the solar cycle: effect on p‐mode damping rates , 2001 .

[7]  Excitation of stellar p-modes by turbulent convection - II. The Sun , 2001, astro-ph/0101111.

[8]  R. Samadi,et al.  Excitation of stellar p-modes by turbulent convection: 1. Theoretical formulation , 2001, astro-ph/0101109.

[9]  William J. Chaplin,et al.  Observational Upper Limits to Low-Degree Solar g-Modes , 2000 .

[10]  W. Chaplin,et al.  Solar p-mode excitation: further insight from recent low-ℓ BiSON helioseismological data , 1998 .

[11]  P. Scherrer,et al.  Asymmetry in Velocity and Intensity Helioseismic Spectra: A Solution to a Long-standing Puzzle , 1998 .

[12]  J. Christensen-Dalsgaard,et al.  Performance and Early Results from the Golf Instrument Flown on the Soho Mission , 1997 .

[13]  P. Morel.  CESAM: A code for stellar evolution calculations , 1997 .

[14]  Pawan Kumar,et al.  Asymmetries of Solar p-mode Line Profiles , 1996, astro-ph/9610254.

[15]  I. Goldman,et al.  Stellar Turbulent Convection: A Self-consistent Model , 1996 .

[16]  R. K. Ulrich,et al.  The Global Oscillation Network Group (GONG) Project , 1996, Science.

[17]  F. Minh,et al.  Numerical solution of stellar nonradial oscillations: the Galerkin and B-Splines method , 1995 .

[18]  Neil V. Murray.  The Excitation of Solar P-Modes , 1994 .

[19]  J. Harvey,et al.  Asymmetries of solar oscillation line profiles , 1993 .

[20]  Robert L. Kurucz,et al.  New Opacity Calculations , 1991 .

[21]  Jørgen Christensen-Dalsgaard,et al.  The effect of rotation on whole-disc Doppler observations of solar oscillations , 1989 .

[22]  H. P. Jones.  Formation of fourier phase shifts in the solar Nii 6768 Å line , 1989 .

[23]  Douglas Gough,et al.  On the interpretation of five-minute oscillations in solar spectrum line shifts. , 1982 .