On the Mechanism of Hard X-Ray Emission from Magnetars
Beloborodov, Andrei M., On the Mechanism of Hard X-Ray Emission from Magnetars, ApJ, 762, 13 (2013) (ADS)
(click on the image for a larger version)
Here is a "magnetar" flare; perhaps magnetars are unfamiliar to many solar
physicists - they are certain neutron stars - but the event cartoonized
here sure looks like a solar
flare.
But It is really different: the cartoon shows
relativistic particles being ejected into the footpoints of a solar-like
magnetic loop, where they pair-produce in regions where B ~ 10^13 G, not
very solar-like, and eventually hard X-rays become the product via a cascade
of bremsstrahlung and pair production.
In the case of the Sun the particle acceleration is so feeble that the hard
X-ray signature is just the bremsstrahlung bit.
Note that there is no hint of any magnetic reconnection in this picture.
But that has been proposed, for want of any other explanation, in this context
as well as for solar-flare energy release.
Here is a "magnetar" flare; perhaps magnetars are unfamiliar to many solar physicists - they are certain neutron stars - but the event cartoonized here sure looks like a solar flare. But It is really different: the cartoon shows relativistic particles being ejected into the footpoints of a solar-like magnetic loop, where they pair-produce in regions where B ~ 10^13 G, not very solar-like, and eventually hard X-rays become the product via a cascade of bremsstrahlung and pair production. In the case of the Sun the particle acceleration is so feeble that the hard X-ray signature is just the bremsstrahlung bit.
Note that there is no hint of any magnetic reconnection in this picture. But that has been proposed, for want of any other explanation, in this context as well as for solar-flare energy release.