The energy supply to X-ray bright points

Citation
L. Mcdonald et al., The energy supply to X-ray bright points, SOLAR PHYS, 196(1), 2000, pp. 137-156
Citations number
28
Categorie Soggetti
Space Sciences
Journal title
SOLAR PHYSICS
ISSN journal
00380938 → ACNP
Volume
196
Issue
1
Year of publication
2000
Pages
137 - 156
Database
ISI
SICI code
0038-0938(200009)196:1<137:TESTXB>2.0.ZU;2-A
Abstract
X-ray bright points (XBPs) are usually assumed to be isolated structures in the solar atmosphere that are powered exclusively by magnetic reconnection . We analyse a large XBP that does not satisfy this assumption. The XBP is observed to be connected to an active region approximately 280 000 km away by a magnetic loop. We find that the soft X-ray intensity and thermal energ y of the XBP are very sensitive to the existence of the magnetic loop. Both the intensity and energy decrease significantly at the times when the loop disappears, indicating that the loop is a medium for energy transfer from the active region to the XBP. We deduce that the mechanism for the energy t ransfer is most likely to be Alfven or fast-mode magnetoacoustic waves crea ted by photospheric motions in the active region. These waves can dissipate energy at the density gradient between the XBP and the loop via phase mixi ng or resonant absorption.