Solar hydrogen-Lyman continuum observations with SOHO/SUMER

Abstract

In this work we analyze the emission of the H Lyman continuum (HI LyC) in the Quiet Sun (QS) and a solar prominence, in order to derive information on the temperature of the emitting plasma. We used the spectral atlas obtained with SOHO/SUMER detector A in 1999 (Parenti et al. 2005, A&A, 443, 679). The high spectral resolution of this instrument allows a good selection of the continuum, free from emission lines. However, in the HI LyC wavelength domain, the data suffer from large radiometric uncertainties, which lead us to use detector B as a reference. We obtained electron temperatures of 8281 K ± 280 K and 7564 K ± 230 K in two separate parts of the prominence.