Magnetic Flux Cancellation as the Origin of Solar Quiet-region Pre-jet Minifilaments

Abstract

We investigate the origin of ten solar quiet region pre-jet minifilaments, using EUV images from SDO/AIA and magnetograms from SDO/HMI. We recently found (Panesar et al. 2016b) that quiet region coronal jets are driven by minifilament eruptions, where those eruptions result from flux cancelation at the magnetic neutral line under the minifilament. Here, we study the longer-term origin of the pre-jet minifilaments themselves. We find that they result from flux cancelation between minority-polarity and majority-polarity flux patches. In each of ten pre-jet regions, we find that opposite-polarity patches of magnetic flux converge and cancel, with a flux reduction of 10-40% from before to after the minifilament appears. For our ten events, the minifilaments exist for periods ranging from 1.5 hr to two days before erupting to make a jet. Apparently, the flux cancelation builds highly sheared field that runs above and traces the neutral line, and the cool-transition-region-plasma minifilament forms in this field and is suspended in it. We infer that the convergence of the opposite-polarity patches results in reconnection in the low corona that builds a magnetic arcade enveloping the minifilament in its core, and that the continuing flux cancelation at the neutral line finally destabilizes the minifilament field so that it erupts and drives the production of a coronal jet. Thus our observations strongly support that quiet region magnetic flux cancelation results in both the formation of the pre-jet minifilament and its jet-driving eruption.

Fine-scale Explosive Energy Release at Sites of Prospective Magnetic Flux Cancellation in the Core of the Solar Active Region Observed by Hi-C 2.1, IRIS, and SDO

“…Although we do not rule out other possibilities, the observations of flux convergence at the base of events suggests that flux cancellation could play an important role in triggering several of these events, in accord with many recent similar findings of flux cancellation leading to jet eruptions (Huang et al 2015;Panesar et al 2016Panesar et al , 2017Tiwari et al 2016Tiwari et al , 2018Sterling et al 2017Sterling et al , 2018Panesar et al 2018a;López Fuentes et al 2018). As was first proposed by van Ballegooijen & Martens (1989) and Moore & Roumeliotis (1992), and has been observationally confirmed (e.g., Panesar et al 2016Panesar et al , 2017Panesar et al , 2018aTiwari et al 2018;Sterling et al 2018;Chintzoglou et al 2019), the process of flux cancellation (driven by converging photospheric flows) can prepare and trigger the magnetic field that explodes in a flare eruption. The magnetic explosion is either confined (does not produce a surge, jet, or CME) or ejective (produces a surge, jet, or CME) (e.g., Machado et al 1988;Moore et al 2001).…”

“…In this mechanism, instead of flux emergence, flux cancellation leads to and triggers the jet/surge eruption. A twisted flux rope forms by flux cancellation (van Ballegooijen & Martens 1989;Panesar et al 2017;Sterling et al 2018), which is then triggered (to erupt and drive internal and external reconnections as in Figure 15) by further flux cancellation (van Ballegooijen & Martens 1989;Panesar et al 2016Panesar et al , 2017Sterling et al 2017;Panesar et al 2018a,b). Recent theoretical models support this scenario (Wyper et al 2017(Wyper et al , 2019.…”

Unambiguous Evidence of Filament Splitting-induced Partial Eruptions

“…Prominent examples are the Halloween events in AR10468 on 2003 October28 and 29 (Zuccarello et al 2009). The phenomenon also occurs during asymmetric filament eruptions (Tripathi et al 2006a), even on smaller scales, including minifilaments (Panesar et al 2017). Such horizontally split partial eruptions arise naturally if a fully coherent MFR has not (yet) formed, but the source region is composed of MFR and arcade sections (Guo et al 2010b(Guo et al , 2013Chintzoglou et al 2015).…”

Emergence of small-scale magnetic flux in the quiet Sun

“…10). Similar dimmings can be produced by mini-CMEs (Innes et al 2009) and/or mini-filaments (see e.g., Panesar et al 2017) and recent high-resolution observations revealed that eruptions from coronal bright points are common (Mou et al 2018), and their magnetic topologies are complicated enough to support relevant driving mechanisms (Galsgaard et al 2019). We cannot conclude if this applies to our case since our EFR has a much shorter lifetime and smaller spatial extent than the coronal bright points usually studied; the highresolution magnetic field observations that would allow modeling are sparse.…”