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Session 74 - The Quiet & Active Sun.
Display session, Friday, January 09
Exhibit Hall,

[74.13] Electron Temperature Distribution in Coronal Holes

C. D. Halas, S. R. Habbal (SAO), M. Penn (Natl. Solar Obs.), H. Uitenbroek, R. Esser (SAO), R. Altrock (Natl. Solar Obs.), M. Guhathakurta (GSFC/NASA)

Knowledge of the electron temperature within coronal holes is extremely important for constructing solar wind models and for understanding the coronal heating process. We report on the two-dimensional CCD observations of the Fe IX 4585, Fe X 6374, Fe XI 7892 and Fe XIV 5303 Åemission lines made using a coronagraph at the National Solar Observatory at Sacramento Peak. These iron lines, which have a peak formation temperature of 5 10^5, 10^6, 1.2 10^6, and 2 10^6 K, respectively, allow the examination of different temperature plasmas within the same large scale magnetic structure. To account for possible line of sight ambiguities from hot material in the foreground or background of the coronal hole, Yohkoh data were used to determine the extent of the coronal hole along the line of sight. Intensities and widths of these spectral lines as a function of heliocentric distance out to 1.15 R_s will be presented. A comparison will be made between coronal hole and streamer observations.

Program listing for Friday