Probing flare-associated eruptions on AB Doradus via X-ray absorption variations

Source abstract

Abstract In this work, we investigate eruptive phenomena associated with X-ray flares on AB Doradus using observations from XMM-Newton. Our aim is to detect such events with the help of continuous X-ray absorption. The variation in the hydrogen column density (NH) is used as a primary diagnostic to detect such absorption or spectral hardening in the soft X-ray band below 1–2 keV. These variations may represent the signatures of the eruptive processes associated with flares, such as stellar prominences, failed eruptions or coronal mass ejections. We applied a time-resolved spectroscopy technique to track changes in the absorption parameter during flaring episodes. Our analysis shows statistically significant enhancements in NH, spanning from 0.3 to 3.4×1020 cm−2 during the flare and post-flare intervals. Out of six datasets, two sets containing multiple-overlapped flares show significant fluctuations and the remaining showed no such variations in NH. These variations indicate the presence of dynamic absorbing material along the line of sight and point to ongoing physical processes within the stellar corona. This article is part of the theme issue ‘Transferable mechanisms in the oscillatory processes of solar and stellar flares’.