Investigation of Coronal Loop Temperatures using Three EUV Filters and Implications for Future Work with Solar-B

摘要

In 2002 Chae et al. proposed a two filter ratio method for determining unambiguous temperature values for the plasma in the solar corona. When applying this method to SOHO/EIT it was found that outside the range of 0.7 - 4 MK the errors for the instrument response functions were so large that the values could not be trusted. This paper analyses a SOHO/EIT data set of loops at the solar limb. It was found that none of the points taken from along the coronal structure sat on the colour-colour curve. This could be due to a number of different reasons such as the time lapse between the three EUV images, the fairly poor resolution of EIT, plasma flows along the loop or perhaps looking through a multi-thermal atmosphere. Considering the latter, using a simple two temperature approach, it was found that it is possible to reproduce our results in this way.