POSTER PAPER 1.09
Line Shift Variations in Solar Transition Region Lines
J.G. Doyle, M. Madjarska, J. Giamikakis, L. Teriaca, and I.
Roussev
Institute: Armagh Observatory
Institute: Dept. of Physics, Univ. of Athens
Institute: Osservatorio Astrofisico di Arcetri
Institute: High Altitude Observatory
Contact Email: jgd@star.arm.ac.uk
Abstract:
Two high time cadence datasets, taken in
C III 977 A and O VI 1032 A were analysed in an effort to
establish the extent of the variability in the Doppler-shift of typical
mid-transition region lines. In C III, the shortest time-scale
variability seems to occur in the network boundary regions where the line-shift
can vary by 7-8 km s-1 in less than 1 min. The internetwork region also
shows variability although this tends to be longer lived, ~2-3 mins. The
average C III line-shift in all regions is for a red-shift of
~8 km s-1 in very good
agreement with that derived by others. Furthermore, there does not seem to be
any obvious difference in the average line-shift in network and internetwork
regions. On a few rare occasions, the C III line was blue-shifted. The
O VI line was also red-shifted with the network region showing evidence for a
periodicity. These observations were compared to model line profiles based on
the response
of a 2D MHD environment representing the solar transition region to micro-scale
energy depositions. A variety of temperatures at which the energy deposition
takes place as well as the amount of energy deposited was examined.
Index Keywords: Down-flow; Transition Region; Line Profiles
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Manuscript submitted: 2001-Sep-6
"The Future of Cool-Star Astrophysics", 2003, Eds. A. Brown,
G. M. Harper, & T. R. Ayres.
Proceedings of 12th Cambridge Workshop on Cool Stars, Stellar Systems,
& The Sun,
© 2003 University of Colorado.