Liu, Rui and David Alexander, Hard X-ray Emission in Kinking Filaments, ApJ, 697, 999-1009 (2009) (ADS)
(click on the image for a larger version)
It is a failed eruption, caught
in an expanded state with a large simple twist.
This fairly common geometry makes a clear suggestion that flare energy release
(specifically, hard X-rays)
might result from magnetic reconnection driven by a
kink instability,
forcing somewhat antiparallel fields together.
Indeed the writhing motions of erupting filaments, and their clear tendency to heat
up (rather than cool off, as might be expected from expansion) as they rise,
has spawned a widely-held idea that the fundamental energy release
of a solar flare comes from an instability that couuld be described
as an ideal MHD instability.
Reconnection would then happen when, where, and if it could.
That seems to be the idea here, and why not?
But in a case like this, if the reconnection is forced by kink motions, the energy
released must come from the kink flows themselves ultimately, rather than from the
immediate annihilation of the field.
It is a failed eruption, caught in an expanded state with a large simple twist. This fairly common geometry makes a clear suggestion that flare energy release (specifically, hard X-rays) might result from magnetic reconnection driven by a kink instability, forcing somewhat antiparallel fields together. Indeed the writhing motions of erupting filaments, and their clear tendency to heat up (rather than cool off, as might be expected from expansion) as they rise, has spawned a widely-held idea that the fundamental energy release of a solar flare comes from an instability that couuld be described as an ideal MHD instability. Reconnection would then happen when, where, and if it could. That seems to be the idea here, and why not? But in a case like this, if the reconnection is forced by kink motions, the energy released must come from the kink flows themselves ultimately, rather than from the immediate annihilation of the field.