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Session 33 - Dynamics of Solar Magnetic Fields.
Oral session, Tuesday, June 11
The radial variation of temperature in the inner corona is examined using long exposure Yohkoh images for two regions of diffuse (quiet) corona. The results indicate a steady radial increase of temperature for both regions, out to 0.7 and 0.9 solar radii above the limb, respectively. We find that the filter ratio data for the two regions is well fitted in each case by integration over the line of sight of a model radial atmosphere in hydrostatic equilibrium and with a temperature profile due to a conserved inward heat flux. An Abel inversion process is also applied to the data, and this gives results consistent with the radially symmetric, conserved heat flux model. These results imply that the non-thermal energy responsible for heating these pieces of the quiet corona is being deposited beyond the observed range of heights. However, the diffuse regions we examined are believed to be mainly closed field regions, and so the radial models require careful interpretation. We discuss the implications for coronal heating in these regions, and compare this result with other recent determinations of the temperature in the inner corona.
This work was supported in part by NASA grant NAS 8-37334. The authors acknowledge also support from Air Force grant F49620-95-1-0008 and NASA grant NAGW-2265.
Program listing for Tuesday