Tuning the Exospace Weather Radio for Stellar Coronal Mass Ejections
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Alvarado-Gómez_2020_ApJ_895_47.pdf
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Author
Fraschetti, Federico
Affiliation
Univ Arizona, Dept Planetary Sci, Lunar & Planetary LabIssue Date
2020-05-22Keywords
Magnetohydrodynamical simulationsSolar flares
Stellar flares
Solar coronal mass ejections
Solar coronal mass ejection shocks
Stellar winds
Solar wind
Solar radio emission
Stellar magnetic fields
Solar magnetic fieldsStellar coronaeRadio bursts
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IOP PUBLISHING LTDCitation
Alvarado-Gómez, J. D., Drake, J. J., Fraschetti, F., Garraffo, C., Cohen, O., Vocks, C., ... & Manchester IV, W. B. (2020). Tuning the Exospace Weather Radio for Stellar Coronal Mass Ejections. The Astrophysical Journal, 895(1), 47.Journal
ASTROPHYSICAL JOURNALRights
© 2020. The American Astronomical Society. All rights reserved.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Coronal mass ejections (CMEs) on stars other than the Sun have proven very difficult to detect. One promising pathway lies in the detection of type II radio bursts. Their appearance and distinctive properties are associated with the development of an outward propagating CME-driven shock. However, dedicated radio searches have not been able to identify these transient features in other stars. Large Alfven speeds and the magnetic suppression of CMEs in active stars have been proposed to render stellar eruptions "radio-quiet." Employing 3D magnetohydrodynamic simulations, we study the distribution of the coronal Alfven speed, focusing on two cases representative of a young Sun-like star and a mid-activity M-dwarf (Proxima Centauri). These results are compared with a standard solar simulation and used to characterize the shock-prone regions in the stellar corona and wind. Furthermore, using a flux-rope eruption model, we drive realistic CME events within our M-dwarf simulation. We consider eruptions with different energies to probe the regimes of weak and partial CME magnetic confinement. While these CMEs are able to generate shocks in the corona, those are pushed much farther out compared to their solar counterparts. This drastically reduces the resulting type II radio burst frequencies down to the ionospheric cutoff, which impedes their detection with ground-based instrumentation.ISSN
0004-637XEISSN
1538-4357Version
Final published versionScopus Count
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