Leon,
Dense as a brick... I am not replying to Markus' input anymore. You're right about our Italian friends though. Once I am done with tons of SDO-SC related organizing and resubmitting my loop paper, there is a whole sequence of papers with Trae on coronal loops and flares in queue.
Cheers,
Piet
Leon Golub wrote:
OK, I have to jump in, since there seems to be some confusion about this. Yes, the increase in coronal density comes up from the chromosphere. This has been known for decades and has been well-modeled, especially by the Palermo group. But it is entirely possible for the energy to be deposited in the corona, then travel down (relying on the ambient density) to be deposited and cause evaporation. The pattern of brightness variations that you see does, in fact, change depending on where in the loop the energy is deposited, and can be used to determine where it happened. By seeing how the loop brightens, you can tell where the energy deposition took place. See:
A Brightening Coronal Loop Observed by TRACE. II. Loop Modeling and Constraints on Heating Reale, F.; Peres, G.; Serio, S.; Betta, R. M.; DeLuca, E. E.; Golub, L. Astrophysical Journal, Volume 535, Issue 1, pp. 423-437, 05/2000.
Leon
Markus J. Aschwanden wrote:
On Mar 6, 2009, at 8:44 AM, Klimchuk, James A. (GSFC-6710) wrote:
By the way, I do NOT believe that observations necessarily point to low altitude heating. My view is that observations are consistent with both low altitude and high altitude heating. Perhaps this should be a topic for Loops IV.
Jim
There is no way around to heat up first chromospheric material to fill coronal loops to produce the enhanced soft X-ray and EUV emission we see from coronal loops (like in flares). Any heating mechanism that heats directly in the corona, does not increase the local density, so we would not see any loops.
Markus
Dr. Markus J. Aschwanden Solar & Astrophysics Laboratory Lockheed Martin Advanced Techology Center Org. ADBS, Bldg. 252 3251 Hanover St., Palo Alto, CA 94304, USA Phone: 650-424-4001, FAX: 650-424-3994 URL: http://www.lmsal.com/~aschwand/ e-mail: aschwanden@lmsal.com mailto:aschwanden@lmsal.com _______________________________________ ____________________________________
Loops mailing list Loops@solar.physics.montana.edu https://mithra.physics.montana.edu/mailman/listinfo/loops
Loops mailing list Loops@solar.physics.montana.edu https://mithra.physics.montana.edu/mailman/listinfo/loops