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 $V$-parameter and the first derivative of the total line profile intensity, were modified by applying a linear integral operator $\hat{L}$ to the both sides of this relation. As the operator $\hat{L}$, 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 ${\alpha }^2$ CVn, young O-type star ${\theta }^1$ 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.

11 pages, 6 figures

References in corpus (5)

• Searching for links between magnetic fields and stellar evolution. I. A survey of magnetic fields in open cluster A- and B-type stars with FORS1
• Discovery of magnetic fields in the beta Cephei star xi^1 CMa and in several Slowly Pulsating B stars
• Magnetic field measurements of O stars with FORS1 at the VLT
• Exploring the origin of magnetic fields in massive stars: II. New magnetic field measurements in cluster and field stars
• Microvariability of Line Profiles in the Spectra of OB Stars II: $\delta$Ori A