Study of the observed intensity variation along EUV coronal loops

LÓPEZ FUENTES, M.C.; KLIMCHUK, J.A.; MANDRINI, C.H.

Mysore

Congreso; 39th COSPAR General Assemby; 2012

COSPAR

The variation of EUV intensity with position along coronal loops is an important constraint for theories of loop heating. For example, thermal nonequilibrium that results from steady heating concentrated at the loop footpoints predicts an intensity structure that is both highly nonuniform and asymmetric (Klimchuk, Karpen, Antiochos, 2010, ApJ, 714, 1239). We have studied the variation of the EUV intensity along coronal loops observed with the Transition Region and Coronal Explorer (TRACE). Here, we present a series of TRACE observations that show that the intensity along loops is highly uctuating (spatially) around a nearly constant level. Although during the data processing we carefully subtracted the background contribution, we interpret the observed pronounced uctuations to be mainly a background residual e ect. However, we cannot rule out the possibility that part of these variations are intrinsic to the loops. In any case, the studied observations seem to be inconsistent with the intensity proles predicted by some numerical studies.