Numerical simulation of the internal plasma dynamics of post-flare loops

CARLOS FERNÁNDEZ, ANDREA COSTA, SERGIO ELASKAR, WALKIRIA SCHULZ

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

Wiley-Blackwell

Lugar: Hoboken (EE.UU.) - Oxford (Reino Unido); Año: 2009

0035-8711

We integrate the MHD ideal equations of a slender flux tube to simulate the internalplasma dynamics of coronal post-flare loops. We study the onset and evolution of the internalplasma instability to compare with observations and to gain insight into physical processes andcharacteristic parameters associated with flaring events. The numerical approach uses a finite- volume Harten-Yee TVD scheme to integrate the 1D1/2 MHD equations specially designed tocapture supersonic flow discontinuities. We could reproduce the observational sliding downand upwardly behavior of brightening features along magnetic threads of an event occurredon October 1st, 2001. We show that high–speed downflow perturbations, usually interpretedas slow magnetoacoustic waves, could be better interpreted as slow magnetoacoustic shockwaves. This result was obtained considering adiabaticity in the energy balance equation. However,a time–dependent forcing from the basis is needed to reproduce the reiteration of theevent which resembles observational patterns -commonly known as quasi–periodic pulsations(QPPs)- which are related with large scale characteristic longitudes of coherence. This resultreinforces the interpretation that the QPPs are a response to the pulsational flaring activity.