TRACE Observation of Damped Coronal Loop Oscillations: Implications for Coronal Heating
V. M. Nakariakov,
1
L. Ofman,
2*
E. E. DeLuca,
3
B. Roberts,
1
J. M. Davila
4
The imaging telescope on board the Transition Region and Coronal
Explorer (TRACE) spacecraft observed the decaying transversal oscillations of a long [(130 ± 6) × 106
meters], thin [diameter (2.0 ± 0.36) × 106
meters], bright coronal loop in the 171 angstrom FeIX
emission line. The oscillations were excited by a solar flare in the
adjacent active region. The decay time of the oscillations is 14.5 ± 2.7 minutes for an oscillation with a frequency 3.90 ± 0.13 millihertz. The coronal dissipation coefficient is estimated to be
eight to nine orders of magnitude larger than the theoretically predicted classical value. The larger dissipation coefficient may solve
existing difficulties with wave heating and reconnection theories.
1 School of Mathematical and Computational Sciences,
University of St. Andrews, St. Andrews, Fife KY16 9SS, Scotland.
2 Raytheon ITSS/NASA Goddard Space Flight Center, 682, Greenbelt, MD 20771, USA.
3 Harvard-Smithsonian Center for
Astrophysics, Cambridge, MA 02138, USA.
4 NASA Goddard Space
Flight Center, 682, Greenbelt, MD 20771, USA.
*
To whom correspondence should be addressed. E-mail:
leon.ofman{at}gsfc.nasa.gov
