COMPARING SPATIAL DISTRIBUTIONS OF SOLAR PROMINENCE MASS DERIVED FROM CORONAL ABSORPTION

In a previous study, Gilbert et al. derived the column density and total mass of solar prominences using a new technique, which measures how much coronal radiation in the Fe XII (195 angstrom) spectral band is absorbed by prominence material, while considering the effects of both foreground and background radiation. In the present work, we apply this method to a sample of prominence observations in three different wavelength regimes: one in which only H(0) is ionized (504 angstrom < lambda < 911 angstrom), a second where both H(0) and He(0) are ionized (228 angstrom < lambda < 504 angstrom), and finally at wavelengths where H(0), He(0), and He(+) are all ionized (lambda < 228 angstrom). This approach, first suggested by Kucera et al., permits the separation of the contributions of neutral hydrogen and helium to the total column density in prominences. Additionally, an enhancement of the technique allowed the calculation of the two-dimensional (2D) spatial distribution of the column density from the continuum absorption in each extreme-ultraviolet observation. We find the total prominence mass is consistently lower in the 625 angstrom observations compared to lines in the other wavelength regimes. There is a significant difference in total mass between the 625 angstrom and 195 angstrom lines, indicating the much higher opacity at 625 angstrom is causing a saturation of the continuum absorption and thus, a potentially large underestimation of mass.