RHESSI Science Nugget No. 192, "Kappa Distribution" (by Mitsuo Oka, Berkeley) - A simpler function fits both thermal and non-thermal hard X-ray components simultaneously.
See http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/Kappa_Distribution
Older Nuggets are available at http://sprg.ssl.berkeley.edu/~tohban/wiki/index.php/RHESSI_Science_Nuggets (the current series, 2008-present), and at http://sprg.ssl.berkeley.edu/~tohban/nuggets/ (the original series, 2005-2008).
We publish these at roughly two-week intervals and welcome contributions, which should be related, at least loosely, to RHESSI science.