Magnetic Flux of Active Regions Determining the Eruptive Character of Large Solar Flares. (arXiv:2007.08127v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Li_T/0/1/0/all/0/1">Ting Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hou_Y/0/1/0/all/0/1">Yijun Hou</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_S/0/1/0/all/0/1">Shuhong Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_J/0/1/0/all/0/1">Jun Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_L/0/1/0/all/0/1">Lijuan Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Veronig_A/0/1/0/all/0/1">Astrid M. Veronig</a>
We establish the largest eruptive/confined flare database to date and analyze
322 flares of emph{GOES} class M1.0 and larger that occurred during
2010$-$2019, i.e., almost spanning the entire solar cycle 24. We find that the
total unsigned magnetic flux ($Phi$$_{AR}$) of active regions (ARs) is a key
parameter in governing the eruptive character of large flares, with the
proportion of eruptive flares exhibiting a strong anti-correlation with
$Phi$$_{AR}$. This means that an AR containing a large magnetic flux has a
lower probability for the large flares it produces to be associated with a
coronal mass ejection (CME). This finding is supported by the high positive
correlation we obtained between the critical decay index height and
$Phi$$_{AR}$, implying that ARs with a larger $Phi$$_{AR}$ have a stronger
magnetic confinement. Moreover, the confined flares originating from ARs larger
than 1.0$times$$10^{23}$ Mx have several characteristics in common: stable
filament, slipping magnetic reconnection and strongly sheared post-flare loops.
Our findings reveal new relations between the magnetic flux of ARs and the
occurrence of CMEs in association with large flares. These relations obtained
here provide quantitative criteria for forecasting CMEs and adverse space
weather, and have also important implications for “superflares” on solar-type
stars and stellar CMEs.
We establish the largest eruptive/confined flare database to date and analyze
322 flares of emph{GOES} class M1.0 and larger that occurred during
2010$-$2019, i.e., almost spanning the entire solar cycle 24. We find that the
total unsigned magnetic flux ($Phi$$_{AR}$) of active regions (ARs) is a key
parameter in governing the eruptive character of large flares, with the
proportion of eruptive flares exhibiting a strong anti-correlation with
$Phi$$_{AR}$. This means that an AR containing a large magnetic flux has a
lower probability for the large flares it produces to be associated with a
coronal mass ejection (CME). This finding is supported by the high positive
correlation we obtained between the critical decay index height and
$Phi$$_{AR}$, implying that ARs with a larger $Phi$$_{AR}$ have a stronger
magnetic confinement. Moreover, the confined flares originating from ARs larger
than 1.0$times$$10^{23}$ Mx have several characteristics in common: stable
filament, slipping magnetic reconnection and strongly sheared post-flare loops.
Our findings reveal new relations between the magnetic flux of ARs and the
occurrence of CMEs in association with large flares. These relations obtained
here provide quantitative criteria for forecasting CMEs and adverse space
weather, and have also important implications for “superflares” on solar-type
stars and stellar CMEs.
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