Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-12-05
Astronomy and Astrophysics
Astrophysics
14 pages, 5 figures, accepted for Ap.J
Scientific paper
10.1086/339159
We have recently developed the capability to make solar vector (Stokes IQUV) magnetograms using the infrared line of MgI at 12.32 microns. On 24 April 2001, we obtained a vector magnetic map of solar active region NOAA 9433, fortuitously just prior to the occurrence of an M2 flare. Examination of a sequence of SOHO/MDI magnetograms, and comparison with ground-based H-alpha images, shows that the flare was produced by the cancellation of newly emergent magnetic flux outside of the main sunspot. The very high Zeeman-sensitivity of the 12-micron data allowed us to measure field strengths on a spatial scale which was not directly resolvable. At the flare trigger site, opposite polarity fields of 2700 and 1000 Gauss occurred within a single 2 arc-sec resolution element, as revealed by two resolved Zeeman splittings in a single spectrum. Our results imply an extremely high horizontal field strength gradient (5 G/km) prior to the flare, significantly greater than seen in previous studies. We also find that the magnetic energy of the cancelling fields was more than sufficient to account for the flare's X-ray luminosity.
Deming Drake
Jennings Donald E.
McCabe George
Moran Thomas
Sada Pedro
No associations
LandOfFree
Solar Magnetic Field Studies Using the 12-Micron Emission Lines. IV. Observations of a Delta-Region Solar Flare 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 Solar Magnetic Field Studies Using the 12-Micron Emission Lines. IV. Observations of a Delta-Region Solar Flare, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solar Magnetic Field Studies Using the 12-Micron Emission Lines. IV. Observations of a Delta-Region Solar Flare will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-174099