Friends,

I'm glad to see that the EM loci method is put on a more quantitative basis,
especially in relationship to Gaussian DEM functions with variable temperature
spread. While the two methods can now being used interchangably thanks to
this recent nice study of Landi and Klimchuk, the biggest diagnostic problem for 
coronal loops is (in my view) still the proper background subtraction.
Every contaminations from background fluxes introduces always a bias
towards broader multi-thermal DEMs. This problem is even worse for AIA
data, because more filters involve more confusion. 

Looking forward to a patented background subtraction technique.

Cheers,
Markus



On Sep 23, 2010, at 6:25 AM, Klimchuk, James A. (GSFC-6710) wrote:

Friends,
 
     The EM loci technique is frequently used to access whether a plasma is isothermal.  The attached paper addresses the uncertainty in this technique and proposes a way to determine the range of thermal distribution widths that are consistent with a set of emission line data.
 
Cheers,
Jim
 
********************************************************************************
James A. Klimchuk
NASA Goddard Space Flight Center
Solar Physics Lab, Code 671
Bldg. 21, Rm. 158
Greenbelt, MD  20771
USA
 
Phone:  1-301-286-9060
Fax:      1-301-286-7194
 
No endorsement by NASA is implied for any correspondence related to my role as an officer of professional organizations (American Geophysical Union, American Astronomical Society, International Astronomical Union).
 
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Dr. Markus J. Aschwanden
Solar & Astrophysics Laboratory
Lockheed Martin Advanced Techology Center
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3251 Hanover St., Palo Alto, CA 94304, USA
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