Magnetic thread twisting in a simulated solar atmosphere. (arXiv:2208.02763v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Sumner_C/0/1/0/all/0/1">Chloe Sumner</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Taroyan_Y/0/1/0/all/0/1">Youra Taroyan</a>
Context. Plasma inflows accompany a variety of processes in the solar
atmosphere such as heating of coronal loops and formation of prominences.
Aims. We model a stratified solar atmosphere, within which a simulated
prominence thread experiences density accumulation via a plasma inflow designed
to mimic the formation process. We aim to investigate the interaction of such a
system with torsional perturbations, and the possible consequences.
Methods. The linearised equations of motion and induction are integrated to
analyse the spatial and temporal evolution of torsional perturbations that are
randomly driven at the photospheric footpoints.
Results. Our results demonstrate that magnetic threads will experience twist
amplification. Different sources and sinks of energy and the corresponding
amplification mechanisms are identified. Threads reaching chromospheric heights
are most susceptible to magnetic twisting with the maximum twist occurring near
their footpoints. The amplifying twists are associated with a standing wave
behaviour along the simulated threads.
Conclusions. Our work suggests that torsional perturbations may be amplified
within prominence threads, with strong magnetic twists forming at the
footpoints. The amplification process is facilitated by small length scales in
the background magnetic field. On the other hand, a small length scale in the
background density inhibits growth. Possible consequences of the amplified
twists, including their role in supporting the dense plasma within a prominence
structure are discussed.
Context. Plasma inflows accompany a variety of processes in the solar
atmosphere such as heating of coronal loops and formation of prominences.
Aims. We model a stratified solar atmosphere, within which a simulated
prominence thread experiences density accumulation via a plasma inflow designed
to mimic the formation process. We aim to investigate the interaction of such a
system with torsional perturbations, and the possible consequences.
Methods. The linearised equations of motion and induction are integrated to
analyse the spatial and temporal evolution of torsional perturbations that are
randomly driven at the photospheric footpoints.
Results. Our results demonstrate that magnetic threads will experience twist
amplification. Different sources and sinks of energy and the corresponding
amplification mechanisms are identified. Threads reaching chromospheric heights
are most susceptible to magnetic twisting with the maximum twist occurring near
their footpoints. The amplifying twists are associated with a standing wave
behaviour along the simulated threads.
Conclusions. Our work suggests that torsional perturbations may be amplified
within prominence threads, with strong magnetic twists forming at the
footpoints. The amplification process is facilitated by small length scales in
the background magnetic field. On the other hand, a small length scale in the
background density inhibits growth. Possible consequences of the amplified
twists, including their role in supporting the dense plasma within a prominence
structure are discussed.
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