Ability of a geometric disk warp to reproduce extreme, rapid column density variability in GRS 1915+105

Ascertain whether a geometric warp of the accretion disk can account for the extreme column density variations observed on short timescales during the obscured X-ray phase of GRS 1915+105.

Background

GRS 1915+105 has entered an obscured phase characterized by large, rapidly varying intrinsic absorption, sometimes reaching Compton-thick levels. One proposed explanation is a warped or puffed-up outer disk intercepting the line of sight.

The authors point out that the magnitude and rapidity of the observed column density variations may be challenging for a purely geometric warp to explain, raising the question of whether geometric warping alone can reproduce the observed variability or if alternative mechanisms (e.g., clumpy disk winds) are required.