[Loops] new paper on IRIS diagnostics for coronal heating and accelerated particles

[Paola Testa]

Dear all,

you might be interested in the following paper that has just been 
published on Science:
"Evidence of non-thermal particles in coronal loops heated impulsively 
by nanoflares"
It can be downloaded from astro-ph: http://arxiv.org/abs/1410.6130 or 
directly
from the Science pages: http://www.sciencemag.org/content/346/6207/1255724
The abstract is below.

cheers,
Paola


Abstract:
The physical processes causing energy exchange between the Sun's hot 
corona and its
cool lower atmosphere remain poorly understood. The chromosphere and 
transition region
(TR) form an interface region between the surface and the corona that is 
highly sensitive to
the coronal heating mechanism. High-resolution observations with the 
Interface Region
Imaging Spectrograph (IRIS) reveal rapid variability (~20 to 60 seconds) 
of intensity and
velocity on small spatial scales (?500 kilometers) at the footpoints of 
hot and dynamic
coronal loops. The observations are consistent with numerical 
simulations of heating by
beams of nonthermal electrons, which are generated in small impulsive 
(?30 seconds)
heating events called "coronal nanoflares." The accelerated electrons 
deposit a sizable
fraction of their energy (?10^25 erg) in the chromosphere and TR. Our 
analysis provides tight
constraints on the properties of such electron beams and new diagnostics 
for their
presence in the nonflaring corona.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mithra.physics.montana.edu/pipermail/loops/attachments/20141030/c35bff95/attachment.html>