Emission measure distribution of nanoflare-heated coronal loops

M. LÓPEZ FUENTES; J. A. KLIMCHUK

Cusco

Conferencia; X Conferencia Latinoamericana de Geofísica Espacial (COLAGE); 2014

Asociación Latinoamericana de Geofísica Espacial

In recent years several authors began to study the emission measure (EM) distribution of coronal loop plasmas as a test for coronal heating mechanisms. In particular, it is argued that the amount of emitting plasma at the temperature of maximum emission relative to the plasma at 1 MK is determined by the kind of process producing the heating. The parameter commonly used to characterize the EM distribution is the slope of the log(EM) versus log(T) histogram between the above temperatures. In this work, we analyze the EM distribution obtained from a cellular automaton model of multi-stranded nanoflare-heated coronal loops. Our model is based on the idea that footpoint motions due to photospheric convection produce magnetic stress between the elementary strands that form loops. When the stress becomes critical magnetic energy is released in the form of reconnection events identified as nanoflares. We simulate the plasma response to the nanoflares and obtain the EM distribution of the loop plasma. We test different model parameters combinations within solar values and find that the slopes obtained reproduce the range of slopes found in observations. We discuss the implications of these results for the coronal heating problem.