Modified methods of stellar magnetic field measurements

Abstract

The standard methods of the magnetic field measurement, based on an analysis of the relation between the Stokes Vparameter and the first derivative of the total line profile intensity, were modified by applying a linear integral operatorL to the both sides of this relation. As the operatorL, the operator of the wavelet transform with DOG-wavelets is used. The key advantage of the proposed method is an effective suppression of the noise contribution to the line profile and the Stokes parameter V . The efficiency of the method has been studied using the model line profiles with various noise contributions. To test the proposed method, the spectropolarimetric observations of the A0-type star α 2 CVn, young O-type star θ 1 Ori C and A0 supergiant HD 92207 were used. The longitudinal magnetic field strengths for these stars calculated by our method appeared to be in a good agreement with those determined by other methods.