3D MHD models of the centrifugal magnetosphere from a massive star with an oblique dipole field
Abstract
We present results from new self-consistent 3D MHD simulations of the magnetospheres from massive stars with a dipole magnetic axis that has a non-zero obliquity angle (β) to the star’s rotation axis. As an initial direct application, we compare the global structure of co-rotating disks for nearly aligned (β = 5o) versus half-oblique (β = 45o) models, both with moderately rapid rotation (∼ 0.5 critical). We find that accumulation surfaces broadly resemble the forms predicted by the analytic Rigidly Rotating Magnetosphere (RRM) model, but the mass buildup to near the critical level for centrifugal breakout against magnetic confinement distorts the field from the imposed initial dipole. This leads to an associated warping of the accumulation surface toward the rotational equator, with the highest density concentrated in wings centered on the intersection between the magnetic and rotational equators. These MHD models can be used to synthesize rotational modulation of photometric absorption and H α emission for a direct comparison with observations.
Citation
ud-Doula , A , Owocki , S P , Russell , C , Gagné , M & Daley-Yates , S 2023 , ' 3D MHD models of the centrifugal magnetosphere from a massive star with an oblique dipole field ' , Monthly Notices of the Royal Astronomical Society , vol. 520 , no. 3 , pp. 3947–3954 . https://doi.org/10.1093/mnras/stad345
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
ISSN
0035-8711Type
Journal article
Rights
Copyright © 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.1093/mnras/stad345.
Description
Funding: This work is supported in part by the National Aeronautics and Space Administration under Grant No. 80NSSC22K0628 issued through the Astrophysics Theory Program. AuD and MRG acknowledge support by the National Aeronautics and Space Administration through Chandra Award Numbers TM-22001 and GO223003X, issued by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060. This work used the Bridges2 cluster at the Pittsburgh Supercomputer Center through allocation AST200002 from the Extreme Science and Engineering Discovery Environment (XSEDE), which was supported by National Science Foundation grant number 1548562.Collections
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