Betatron acceleration in a large solar hard X-ray burst.
Brown, J. C. and P. Hoyng, Betatron acceleration in a large solar hard X-ray burst., ApJ, 200, 734-746 (1975) (ADS)
(click on the image for a larger version)
A cartoon aiming at explaining one of the rare coronal hard X-ray
events, ie one with a soft-hard-harder spectral morphology as opposed
to the much more common soft-hard-soft morphology.
Thanks to imaging
and radio observations since TD-1A flew (yes, there was a solar
observatory in space by that name, but not a TD-2A nor a TD-1B!),
we have learned a great deal about such events, but it is still
quite rewarding to read a paper such as this - it anticipated the
twanging
QPP loops, for example, a
big discovery by TRACE and the cornerstone of "coronal seismology."
Also it didn't make the usual mindless appeal to magnetic
reconnection as an explanation, although
certainly at a higher level of thinking one imagines it happening.
As of the date of this note, we can also point out that this paper
also anticipated the
"collapsing trap" physics,
for which there are several more recent cartoons.
Note that the coronal nonthermal sources have current interest because
of recent RHESSI and Fermi discoveries.
A cartoon aiming at explaining one of the rare coronal hard X-ray events, ie one with a soft-hard-harder spectral morphology as opposed to the much more common soft-hard-soft morphology. Thanks to imaging and radio observations since TD-1A flew (yes, there was a solar observatory in space by that name, but not a TD-2A nor a TD-1B!), we have learned a great deal about such events, but it is still quite rewarding to read a paper such as this - it anticipated the twanging QPP loops, for example, a big discovery by TRACE and the cornerstone of "coronal seismology." Also it didn't make the usual mindless appeal to magnetic reconnection as an explanation, although certainly at a higher level of thinking one imagines it happening. As of the date of this note, we can also point out that this paper also anticipated the "collapsing trap" physics, for which there are several more recent cartoons.
Note that the coronal nonthermal sources have current interest because of recent RHESSI and Fermi discoveries.