3D Magnetic Reconnection at an X-Ray Bright Point

Details 3D Magnetic Reconnection at an X-Ray Bright Point 3D Magnetic Reconnection at an X-Ray Bright Point

Sep 1996

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996soph..168..115m&link_type=abstract

Solar Physics, Volume 168, Issue 1, pp.115-133

Physics

44

Scientific paper

On May 1, 1993, a flaring X-ray bright point (XBP) was observed for about 16 hours in the old, disintegrating, bipolar active region (AR) NOAA 7493. During this period, a minor magnetic bipole (1020 Mx) emerged in the region. We have found observational evidence showing that the XBP brightenings were due to magnetic reconnection between the new bipole and pre-existing plage fields. The aim of the present work is to substantiate with magnetic modelling what has been shown by the observations. For this purpose we extrapolate the observed photospheric magnetic fields in the linear force-free approximation and follow its evolution during the lifetime of the XBP. From the computed coronal field lines we determine the location of regions of drastic change in field-line linkage, called ‘quasi-separatrix layers’ or QSLs. QSLs are open layers that behave physically like separatrices: the break down of ideal magnetohydrodynamics and the release of free magnetic energy may occur at these locations when their thickness is small enough. The extrapolated field lines, with photospheric footpoints on both sides of QSLs, match the observed chromospheric and coronal structures (arch filament system, XBP and faint X-ray loops (FXL)). We study also the evolution of the width of the QSL located over the new negative polarity pore: the calculated QSL is very thin (typically less than 100 m) during the lifetime of the XBP, but becomes much thicker (≥ 104 m) after the XBP has faded. Furthermore we show that peaks in X-ray brightness propagate along the FXL with a velocity of ≈ 670 km s-1, starting from the XBP location, implying that the energy is released where the emerging bipole impacts against pre-existing coronal loops. We discuss the possible mechanism of energy transport and conclude that the energy is conducted to the remote footpoints of the FXL by a thermal front. These results strongly support the supposition that the XBP brightness and flaring are due to the interaction of different flux systems, through 3D magnetic reconnection, at QSLs.

Affiliated with

Also associated with

No associations

Rating

3D Magnetic Reconnection at an X-Ray Bright Point does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with 3D Magnetic Reconnection at an X-Ray Bright Point, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and 3D Magnetic Reconnection at an X-Ray Bright Point will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-996617