Context: Detailed hydrodynamic modeling explained several features of a fragment of the core of a Coronal Mass Ejection observed with SoHO/UVCS at 1.7 Rsun on 12 December 1997, but some questions remained unsolved. Aims: We investigate the role of the magnetic fields in the thermal insulation and the expansion of an ejected fragment (cloud) traveling upwards in the outer corona. Methods: We perform MHD simulations including the effects of thermal conduction and radiative losses of a dense spherical or cylindrical cloud launched upwards in the outer corona, with various assumptions on the strength and topology of the ambient magnetic field; we also consider the case of a cylindrical cloud with an internal magnetic field component along its axis. Results: We find that a weak ambient magnetic field (β ˜ 20) with open topology provides both significant thermal insulation and large expansion. The cylindrical cloud expands more than the spherical one.

PAGANO, P., REALE, F., ORLANDO, S., PERES, G. (2007). MHD evolution of a fragment of a CME core in the outer solar corona. ASTRONOMY & ASTROPHYSICS, 464, 753-760 [10.1051/0004-6361:20065866].

MHD evolution of a fragment of a CME core in the outer solar corona

PAGANO, Paolo;REALE, Fabio;PERES, Giovanni
2007-01-01

Abstract

Context: Detailed hydrodynamic modeling explained several features of a fragment of the core of a Coronal Mass Ejection observed with SoHO/UVCS at 1.7 Rsun on 12 December 1997, but some questions remained unsolved. Aims: We investigate the role of the magnetic fields in the thermal insulation and the expansion of an ejected fragment (cloud) traveling upwards in the outer corona. Methods: We perform MHD simulations including the effects of thermal conduction and radiative losses of a dense spherical or cylindrical cloud launched upwards in the outer corona, with various assumptions on the strength and topology of the ambient magnetic field; we also consider the case of a cylindrical cloud with an internal magnetic field component along its axis. Results: We find that a weak ambient magnetic field (β ˜ 20) with open topology provides both significant thermal insulation and large expansion. The cylindrical cloud expands more than the spherical one.
2007
PAGANO, P., REALE, F., ORLANDO, S., PERES, G. (2007). MHD evolution of a fragment of a CME core in the outer solar corona. ASTRONOMY & ASTROPHYSICS, 464, 753-760 [10.1051/0004-6361:20065866].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/5602
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