Homologous compact major blowout-eruption solar flares and their production of broad CMEs

TL;DR

This study investigates the formation of three homologous broad CMEs resulting from sequential blowout-eruption flares in a solar active region, revealing a magnetic-arch-blowout mechanism underlying their development.

Contribution

It demonstrates that homologous broad CMEs originate from a double flux rope system undergoing sequential eruptions within a magnetic-arch-blowout scenario.

Findings

Sequential eruptions produce broad CMEs with increasing angular width.

Magnetic modeling confirms the double flux rope system as the eruption source.

Eruptions follow the magnetic-arch-blowout scenario.

Abstract

We analyze the formation mechanism of three homologous broad coronal mass ejections (CMEs) resulting from a series of solar blowout-eruption flares with successively increasing intensities (M2.0, M2.6, and X1.0). The flares originated from active region NOAA 12017 during 2014 March 28-29 within an interval of approximately 24 hr. Coronal magnetic field modeling based on nonlinear-force-free-field extrapolation helps to identify low-lying closed bipolar loops within the flaring region enclosing magnetic flux ropes. We obtain a double flux rope system under closed bipolar fields for the all the events. The sequential eruption of the flux ropes led to homologous flares, each followed by a CME. Each of the three CMEs formed from the eruptions gradually attain a large angular width, after expanding from the compact eruption-source site. We find these eruptions and CMEs to be consistent with the 'magnetic-arch-blowout' scenario: each compact-flare blowout eruption was seated in one foot of a far-reaching magnetic arch, exploded up the encasing leg of the arch, and blew out the arch to make a broad CME.