Coronal response to magnetically-suppressed CME events in M-dwarf stars. (arXiv:1909.04092v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Alvarado_Gomez_J/0/1/0/all/0/1">Juli&#xe1;n D. Alvarado-G&#xf3;mez</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Drake_J/0/1/0/all/0/1">Jeremy J. Drake</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Moschou_S/0/1/0/all/0/1">Sofia P. Moschou</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Garraffo_C/0/1/0/all/0/1">Cecilia Garraffo</a> (2,1), <a href="http://arxiv.org/find/astro-ph/1/au:+Cohen_O/0/1/0/all/0/1">Ofer Cohen</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Yadav_R/0/1/0/all/0/1">Rakesh K. Yadav</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Fraschetti_F/0/1/0/all/0/1">Federico Fraschetti</a> (1,4) ((1) Center for Astrophysics | Harvard &amp; Smithsonian, (2) Institute for Applied Computational Science – Harvard University, (3) University of Massachusetts at Lowell – Department of Physics &amp; Applied Physics, (4) Dept. of Planetary Sciences-Lunar and Planetary Laboratory – University of Arizona)

We report the results of the first state-of-the-art numerical simulations of
Coronal Mass Ejections (CMEs) taking place in realistic magnetic field
configurations of moderately active M-dwarf stars. Our analysis indicates that
a clear, novel, and observable, coronal response is generated due to the
collapse of the eruption and its eventual release into the stellar wind.
Escaping CME events, weakly suppressed by the large-scale field, induce a
flare-like signature in the emission from coronal material at different
temperatures due to compression and associated heating. Such flare-like
profiles display a distinctive temporal evolution in their Doppler shift signal
(from red to blue), as the eruption first collapses towards the star and then
perturbs the ambient magnetized plasma on its way outwards. For stellar fields
providing partial confinement, CME fragmentation takes place, leading to rise
and fall flow patterns which resemble the solar coronal rain cycle. In strongly
suppressed events, the response is better described as a gradual brightening,
in which the failed CME is deposited in the form of a coronal rain cloud
leading to a much slower rise in the ambient high-energy flux by relatively
small factors ($sim2-3$). In all the considered cases (escaping/confined) a
fractional decrease in the emission from mid-range coronal temperature plasma
occurs, similar to the coronal dimming events observed on the Sun. Detection of
the observational signatures of these CME-induced features requires a sensitive
next generation X-ray space telescope.

We report the results of the first state-of-the-art numerical simulations of
Coronal Mass Ejections (CMEs) taking place in realistic magnetic field
configurations of moderately active M-dwarf stars. Our analysis indicates that
a clear, novel, and observable, coronal response is generated due to the
collapse of the eruption and its eventual release into the stellar wind.
Escaping CME events, weakly suppressed by the large-scale field, induce a
flare-like signature in the emission from coronal material at different
temperatures due to compression and associated heating. Such flare-like
profiles display a distinctive temporal evolution in their Doppler shift signal
(from red to blue), as the eruption first collapses towards the star and then
perturbs the ambient magnetized plasma on its way outwards. For stellar fields
providing partial confinement, CME fragmentation takes place, leading to rise
and fall flow patterns which resemble the solar coronal rain cycle. In strongly
suppressed events, the response is better described as a gradual brightening,
in which the failed CME is deposited in the form of a coronal rain cloud
leading to a much slower rise in the ambient high-energy flux by relatively
small factors ($sim2-3$). In all the considered cases (escaping/confined) a
fractional decrease in the emission from mid-range coronal temperature plasma
occurs, similar to the coronal dimming events observed on the Sun. Detection of
the observational signatures of these CME-induced features requires a sensitive
next generation X-ray space telescope.

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