Application of a New Technique for Deriving Prominence Mass fromSOHOEIT Fexii(19.5 nm) Absorption Features

Total mass of six quiescent prominences estimated from their multi-spectral observations

“…Both values lie in the interval of the total masses estimated here. Later they published the work on a similar analysis of EIT prominence observations made from July 1999 through July 2004 and they found average values of 4.18 × 10 11 kg for quiescent prominences, 9.09 × 10 11 kg for eruptive prominences, and 1.53 × 10 11 kg for surges (Gilbert et al 2006). The average total mass 7.48 × 10 11 kg for prominences studied in this work (the small prominence of observations No.…”

“…The first estimation of the prominence mass using filtergrams was made by Golub et al (1999) using Transition Region and Coronal Explorer (TRACE 1 ) data. Similar studies were made by Gilbert et al (2005Gilbert et al ( , 2006 using observations of EUV Imaging Telescope (EIT; Delaboudinière et al 1995) on board SoHO in the 195 Å channel. In those two works it was shown that it is necessary to estimate an amount of coronal emission behind and in front of the prominence (hereafter referred to as background and foreground radiation, respectively) to determine correctly the amount of absorbed radiation.…”

“…2 excluded) is closer to their average value for eruptive prominences than their average mass of quiescent prominences, but all prominences studied here behaved quiescently and it was not investigated whether any of them erupted later. This discrepancy can be explained in two ways: first, Gilbert et al (2006) took only a dark structure observed in the EUV coronal radiation, which can be only a small part of whole prominence. Instead, we integrated the column density of hydrogen and helium throughout the whole prominence area fixed according to projection of a prominence on the limb as seen in the AIA 304 Å image.…”

“…The estimated values of the total mass and hydrogen column density are comparable with results published in earlier and recent works of other authors. Hydrogen column densities are derived from an amount of the EUV coronal radiation absorbed by a prominence plasma in the resonance continua of hydrogen and helium, similarly to Kucera et al (1998), Golub et al (1999), Gilbert et al (2005Gilbert et al ( , 2006 and Williams et al (2013). Contrary to our method, lack of the coronal emission that would be present in a volume occupied by a cool prominence plasma -the so-called coronal emissivity deficit -was not taken into account or was neglected in those works.…”

“…Thus, we also estimated α for each prominence using indirect measurement from the intensities in the quiet corona just above the limb close to the prominence (the line of sight passing through the whole corona) and on the disc close to its edge (the line of sight passing through the corona in front of the prominence). A similar method for estimation of coronal radiation from behind a prominence was also used by Gilbert et al (2005Gilbert et al ( , 2006. Then we compare the α values estimated from τ 193 /τ 211 with those measured indirectly (see Sect.…”