Monday, March 11, 2013

1303.1851 (Michal Tomczak)

Two solar flares that became X-ray plasma ejections    [PDF]

Michal Tomczak
Solar flares and X-ray plasma ejections (XPEs) occur simultaneously but usually are separated spatially. We present two exceptional events observed by {\sl Yohkoh} in 2001 October 2 (event 1) and 2000 October 16 (event 2), in which features of flares and XPEs are mixed. Namely, the soft and hard X-ray images show intense sources of emission that move dynamically. Both events occurred inside broad active regions showing complicated multi-level structure reaching up to 200 Mm high. Both events show also similar four-stages evolution: (1) a fast rise of a system of loops, (2) sudden changes in their emission distribution, (3) a reconfiguration leading to liberation of large amounts of plasma, (4) a small, static loop as the final remnant. Nevertheless, the events are probably caused by different physical processes: emerging magnetic flux plus reconnection (event 1) and reconnection plus ballooning instability (event 2). Different is also the final destination of the ejected plasma: in the event 1 overlying magnetic fields stop the ejection, in the event 2 the ejection destabilizes the overall magnetic structure and forms a coronal mass ejection (CME).
View original:

No comments:

Post a Comment