Observational and model analysis of a two-ribbon flare possibly induced by a neighbouring blowout jet

TL;DR

This study presents detailed observations and magnetic modeling of a solar blowout jet that likely triggered a confined two-ribbon flare, revealing the jet's dynamics, magnetic field changes, and flare development.

Contribution

It provides the first combined observational and magnetic field analysis linking a blowout jet to a subsequent two-ribbon flare in a solar active region.

Findings

Jet plasma speeds: hot component ~200 km/s, cool component ~130 km/s.

Magnetic field analysis shows an 'X-type' configuration pre-flare and parallel fields post-flare.

Jet activity likely triggered the two-ribbon flare by magnetic perturbation.

Abstract

In this paper, we present unique observations of a blowout coronal jet that possibly triggered a two-ribbon confined C1.2 flare in a bipolar solar active region NOAA 12615 on 2016 December 5. The jet activity initiates at chromospheric/transition-region heights with a small brightening that eventually grows in a larger volume with well developed standard morphological jet features, viz., base and spire. The spire widens up with a collimated eruption of cool and hot plasma components, observed in the 304 and 94 A channels of AIA, respectively. The speed of the plasma ejection, which forms the jet's spire, was higher for the hot component (~200 km/s) than the cooler one (~130 km/s). The NLFF model of coronal fields at pre- and post-jet phases successfully reveal opening of previously closed magnetic field lines with a rather inclined/low-lying jet structure. The peak phase of the jet emission is followed by the development of a two-ribbon flare that shows coronal loop emission in HXRs up to ~25 keV energy. The coronal magnetic fields rooted at the location of EUV flare ribbons, derived from the NLFF model, demonstrate the pre-flare phase to exhibit an "X-type" configuration while the magnetic fields at the post-flare phase are more or less parallel oriented. The comparisons of multi-wavelength measurements with the magnetic field extrapolations suggest that the jet activity likely triggered the two-ribbon flare by perturbing the field in the interior of the active region.