Hopf bifurcations in coronal loops I. Stability conditions for static equilibrium

We study the coupling between the hot plasma confined in a coronal loop and the much colder chromospheric plasma at the footpoints. Considering the coronal heating rate as a control parameter, we find that the static equilibrium becomes unstable for heating rates below a critical value, giving rise...

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Autores principales: Gómez, D., Sicardi Schifino, A., Ferro Fontán, C.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0004637X_v352_n1_p318_Gomez
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spelling todo:paper_0004637X_v352_n1_p318_Gomez2023-10-03T14:01:33Z Hopf bifurcations in coronal loops I. Stability conditions for static equilibrium Gómez, D. Sicardi Schifino, A. Ferro Fontán, C. Hydromagnetics Sun: corona We study the coupling between the hot plasma confined in a coronal loop and the much colder chromospheric plasma at the footpoints. Considering the coronal heating rate as a control parameter, we find that the static equilibrium becomes unstable for heating rates below a critical value, giving rise to the appearance of a stable limit cycle. Starting from the hydrodynamic equations, we derive a model which generalizes the analysis of Kuin and Martens and consistently takes into account the condensation-evaporation process. In this paper, we linearize our equations in order to find the bifurcation point where the stability of the static equilibrium is lost. We also show that this model can provide a natural explanation for the excess widths of EUV spectral lines formed in the transition region. Moreover, we can predict the observed reduction in the broadening of these lines when they form in certain active regions, like quiescent prominences or sunspots. Fil:Gómez, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Sicardi Schifino, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Ferro Fontán, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0004637X_v352_n1_p318_Gomez
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Hydromagnetics
Sun: corona
spellingShingle Hydromagnetics
Sun: corona
Gómez, D.
Sicardi Schifino, A.
Ferro Fontán, C.
Hopf bifurcations in coronal loops I. Stability conditions for static equilibrium
topic_facet Hydromagnetics
Sun: corona
description We study the coupling between the hot plasma confined in a coronal loop and the much colder chromospheric plasma at the footpoints. Considering the coronal heating rate as a control parameter, we find that the static equilibrium becomes unstable for heating rates below a critical value, giving rise to the appearance of a stable limit cycle. Starting from the hydrodynamic equations, we derive a model which generalizes the analysis of Kuin and Martens and consistently takes into account the condensation-evaporation process. In this paper, we linearize our equations in order to find the bifurcation point where the stability of the static equilibrium is lost. We also show that this model can provide a natural explanation for the excess widths of EUV spectral lines formed in the transition region. Moreover, we can predict the observed reduction in the broadening of these lines when they form in certain active regions, like quiescent prominences or sunspots.
format JOUR
author Gómez, D.
Sicardi Schifino, A.
Ferro Fontán, C.
author_facet Gómez, D.
Sicardi Schifino, A.
Ferro Fontán, C.
author_sort Gómez, D.
title Hopf bifurcations in coronal loops I. Stability conditions for static equilibrium
title_short Hopf bifurcations in coronal loops I. Stability conditions for static equilibrium
title_full Hopf bifurcations in coronal loops I. Stability conditions for static equilibrium
title_fullStr Hopf bifurcations in coronal loops I. Stability conditions for static equilibrium
title_full_unstemmed Hopf bifurcations in coronal loops I. Stability conditions for static equilibrium
title_sort hopf bifurcations in coronal loops i. stability conditions for static equilibrium
url http://hdl.handle.net/20.500.12110/paper_0004637X_v352_n1_p318_Gomez
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AT sicardischifinoa hopfbifurcationsincoronalloopsistabilityconditionsforstaticequilibrium
AT ferrofontanc hopfbifurcationsincoronalloopsistabilityconditionsforstaticequilibrium
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