Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2011-02-03
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
43 pages, 13 figures Figure 2 (a) does not show correctly on the arxiv manuscript pdf file
Scientific paper
We show, through a simple patchy reconnection model, that retracting reconnected flux tubes may present elongated regions relatively devoid of plasma, as well as long lasting, dense central hot regions. Reconnection is assumed to happen in a small patch across a Syrovatski\'i (non-uniform) current sheet (CS) with skewed magnetic fields. The background magnetic pressure has its maximum at the center of the CS plane, and decreases toward the edges of the plane. The reconnection patch creates two V-shaped reconnected tubes that shorten as they retract in opposite directions, due to magnetic tension. One of them moves upward toward the top edge of the CS, and the other one moves downward toward the top of the underlying arcade. Rotational discontinuities (RDs) propagate along the legs of the tubes and generate parallel super-sonic flows that collide at the center of the tube. There, gas dynamics shocks that compress and heat the plasma are launched outwardly. The descending tube moves through the bottom part of the CS where it expands laterally in response to the background magnetic pressure. This effect may decrease plasma density by 30 % to 50 % of background levels. This tube will arrive at the top of the arcade that will slow it down to a stop. Here, the perpendicular dynamics is halted, but the parallel dynamics continues along its legs; the RDs are shut down, and the gas is rarified to even lower densities. The hot postshock regions continue evolving, determining a long lasting hot region on top of the arcade. We provide an observational method based on total emission measure and mean temperature, that indicates where in the CS the tube has been reconnected.
Guidoni Silvina E.
Longcope Dana Warfield
No associations
LandOfFree
Density Enhancements and Voids following Patchy Reconnection 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 Density Enhancements and Voids following Patchy Reconnection, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Density Enhancements and Voids following Patchy Reconnection will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-427919