Journal article
THE ZEEMAN EFFECT IN THE SOBOLEV APPROXIMATION: SPLIT MONOPOLE FIELDS AND THE HEARTBEAT STOKES V PROFILE
The Astrophysical journal, Vol.708(1), pp.615-624
2010
DOI: 10.1088/0004-637X/708/1/615
Abstract
We calculate the circularly polarized Stokes V(λ) profile for emission lines, formed in hot-star winds threaded with a weak radial magnetic field. For simplicity, the field is treated as a split monopole under the assumptions that it has been radially combed by the wind, and rotation is not playing a central role. Invoking the weak-field approximation, we find that the V(λ) profile has a characteristic "heartbeat" shape exhibiting multiple sign inversions, which might be mistaken for noise in the absence of theoretical guidance. We also conclude that there is a tendency for the V(λ) profile to integrate to zero on each side of the line separately. The overall scale of V(λ)/I(λ) is set by the ratio of the field strength to the flow speed, B/v, characteristic of the line-forming region, and is of the order of 0.1% for a wind magnetic field B ≅ 100G at depths where the wind speed is v ≅ 100 km s-1. © 2010 . The American Astronomical Society.
Details
- Title: Subtitle
- THE ZEEMAN EFFECT IN THE SOBOLEV APPROXIMATION: SPLIT MONOPOLE FIELDS AND THE HEARTBEAT STOKES V PROFILE
- Creators
- K. G Gayley - University of IowaR Ignace - East Tennessee State University
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.708(1), pp.615-624
- DOI
- 10.1088/0004-637X/708/1/615
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Publisher
- Institute of Physics (IOP)
- Language
- English
- Date published
- 2010
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199806602771
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