Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2011-04-21
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
15 pages, 18 figures
Scientific paper
One of the most dramatic manifestations of solar activity are large-scale coronal bright fronts (CBFs) observed in extreme ultraviolet (EUV) images of the solar atmosphere. To date, the energetics and kinematics of CBFs remain poorly understood, due to the low image cadence and sensitivity of previous EUV imagers and the limited methods used to extract the features. In this paper, the trajectory and morphology of CBFs was determined in order to investigate the varying properties of a sample of CBFs, including their kinematics and pulse shape, dispersion, and dissipation. We have developed a semi-automatic intensity profiling technique to extract the morphology and accurate positions of CBFs in 2.5-10 min cadence images from STEREO/EUVI. The technique was applied to sequences of 171A and 195A images from STEREO/EUVI in order to measure the wave properties of four separate CBF events. Following launch at velocities of ~240-450kms^{-1} each of the four events studied showed significant negative acceleration ranging from ~ -290 to -60ms^{-2}. The CBF spatial and temporal widths were found to increase from ~50 Mm to ~200 Mm and ~100 s to ~1500 s respectively, suggesting that they are dispersive in nature. The variation in position-angle averaged pulse-integrated intensity with propagation shows no clear trend across the four events studied. These results are most consistent with CBFs being dispersive magnetoacoustic waves.
Bloomfield Shaun D.
Gallagher Peter. T.
James McAteer R. T.
Long David M.
No associations
LandOfFree
Deceleration and Dispersion of Large-scale Coronal Bright Fronts 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 Deceleration and Dispersion of Large-scale Coronal Bright Fronts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Deceleration and Dispersion of Large-scale Coronal Bright Fronts will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-178823