TY  - JOUR
A1  - Kliem, Bernhard
A1  - Lin, J.
A1  - Forbes, T. G.
A1  - Priest, E. R.
A1  - Toeroek, T.
T1  - Catastrophe versus instability for the eruption of a toroadal solar magnetic flux
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - The onset of a solar eruption is formulated here as either a magnetic catastrophe or as an instability. Both start with the same equation of force balance governing the underlying equilibria. Using a toroidal flux rope in an external bipolar or quadrupolar field as a model for the current-carrying flux, we demonstrate the occurrence of a fold catastrophe by loss of equilibrium for several representative evolutionary sequences in the stable domain of parameter space. We verify that this catastrophe and the torus instability occur at the same point; they are thus equivalent descriptions for the onset condition of solar eruptions.
KW  - magnetohydrodynamics (MHD)
KW  - Sun: corona
KW  - Sun: coronal mass ejections (CMEs)
KW  - Sun: filaments, prominences
KW  - Sun: flares
KW  - Sun: magnetic fields
Y1  - 2014
U6  - https://doi.org/10.1088/0004-637X/789/1/46
SN  - 0004-637X
SN  - 1538-4357
VL  - 789
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Toeroek, T.
A1  - Leake, J. E.
A1  - Titov, Viacheslav S.
A1  - Archontis, V.
A1  - Mikic, Z.
A1  - Linton, M. G.
A1  - Dalmasse, K.
A1  - Aulanier, Guillaume
A1  - Kliem, Bernhard
T1  - Distribution of electric currents in solar active regions
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
KW  - magnetohydrodynamics (MHD)
KW  - Sun: corona
KW  - Sun: coronal mass ejections (CMEs)
Y1  - 2014
U6  - https://doi.org/10.1088/2041-8205/782/1/L10
SN  - 2041-8205
SN  - 2041-8213
VL  - 782
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - van Driel-Gesztelyi, L.
A1  - Baker, Daniel N.
A1  - Toeroek, T.
A1  - Pariat, E.
A1  - Green, L. M.
A1  - Williams, D. R.
A1  - Carlyle, J.
A1  - Valori, G.
A1  - Demoulin, Pascal
A1  - Kliem, Bernhard
A1  - Long, D. M.
A1  - Matthews, S. A.
A1  - Malherbe, J. -M.
T1  - Coronal magnetic reconnection driven by CME expansion-the 2011 June 7  event
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - Coronal mass ejections (CMEs) erupt and expand in a magnetically structured solar corona. Various indirect observational pieces of evidence have shown that the magnetic field of CMEs reconnects with surrounding magnetic fields, forming, e.g., dimming regions distant from the CME source regions. Analyzing Solar Dynamics Observatory (SDO) observations of the eruption from AR 11226 on 2011 June 7, we present the first direct evidence of coronal magnetic reconnection between the fields of two adjacent active regions during a CME. The observations are presented jointly with a data-constrained numerical simulation, demonstrating the formation/intensification of current sheets along a hyperbolic flux tube at the interface between the CME and the neighboring AR 11227. Reconnection resulted in the formation of new magnetic connections between the erupting magnetic structure from AR 11226 and the neighboring active region AR 11227 about 200 Mm from the eruption site. The onset of reconnection first becomes apparent in the SDO/AIA images when filament plasma, originally contained within the erupting flux rope, is redirected toward remote areas in AR 11227, tracing the change of large-scale magnetic connectivity. The location of the coronal reconnection region becomes bright and directly observable at SDO/AIA wavelengths, owing to the presence of down-flowing cool, dense (1010 cm(-3)) filament plasma in its vicinity. The high-density plasma around the reconnection region is heated to coronal temperatures, presumably by slow-mode shocks and Coulomb collisions. These results provide the first direct observational evidence that CMEs reconnect with surrounding magnetic structures, leading to a large-scale reconfiguration of the coronal magnetic field.
KW  - magnetic reconnection
KW  - magnetohydrodynamics (MHD)
KW  - Sun: corona
KW  - Sun: coronal mass ejections (CMEs)
KW  - Sun: magnetic fields
KW  - Sun: UV radiation
Y1  - 2014
U6  - https://doi.org/10.1088/0004-637X/788/1/85
SN  - 0004-637X
SN  - 1538-4357
VL  - 788
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  -