Local Circumstellar Magnetic Fields Around Evolved Stars

Abstract

I argue that the presence of magnetic fields around evolved stars, e.g., asymptotic giant branch stars, and in PNe, does not necessarily imply that the magnetic field plays a global dynamical role in shaping the circumstellar envelope. Instead, I favor magnetic fields with small coherence lengths, which result from stellar magnetic spots or from jets blown by an accreting companion. Although the magnetic field does not play a global role in shaping the circumstellar envelope, it may enhance local motion (turbulent) via magnetic tension and reconnection. The locally strong magnetic tension may enforce coherence flow which may favor the masing process.

Submitted to MNRAS

References in corpus (5)

• Dynamos in Asymptotic-Giant-Branch Stars As the Origin of Magnetic Fields Shaping Planetary Nebulale
• The symbiotic star CH Cygni. I. Non-thermal bipolar jets
• Turbulent Dynamo in Asymptotic Giant Branch Stars
• Magnetic Collimation in PNe
• X-Ray Emission from Central Binary Systems of Planetary Nebulae

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• Probing the Magnetized Interstellar Medium Surrounding the Planetary Nebula Sh 2-216
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• A hybrid steady-state magnetohydrodynamic dust-driven stellar wind model for AGB stars
• Mapping circumstellar magnetic fields of late-type evolved stars with the Goldreich-Kylafis effect: CARMA observations at $\lambda 1.3$ mm of R Crt and R Leo
• Polarisation of molecular lines in the circumstellar envelope of the post-Asymptotic Giant Branch star OH 17.7-2.0
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• Long-term polarimetric observations of OH127.8+0.0