Comparison of High‐ResolutionTRACEData to Spectroscopic CDS Data for Temperature Determination

Abstract

In this paper we aim to measure the temperature along a specific coronal loop feature which is located in an active region on the western solar limb. The data are taken from Joint Observing Program 146 and consist of high-cadence TRACE triple-filter images coinciding with sparse raster Coronal Diagnostic Spectrometer (CDS) spectroscopic data. The double filter ratio temperature analysis technique is applied to two sets of TRACE images having a 20 minute time gap resulting in temperatures between 1.0 and 1.3 MK. The CDS sparse raster line intensities are used to create emission measure (EM) loci plots determining temperature values over an overlapping 40 minute observing period. These plots appear to be consistent with a line-of-sight isothermal structure which increases in temperature from ~1.20 to ~1.75 MK over the observing period; in contrast, EM loci plots for nearby background pixels depict multithermal emission. Possible reasons for the difference between the TRACE and CDS results and the implications of this analysis on future observations are discussed.