An artist’s view of the “ingestion of a clump” described in Sect. 5.1. Different elements in the figure are not represented to scale. The figures illustrate qualitatively the main phases of the event in chronological order from the top left to the bottom right. In each figure, we plot in the top right corner the XMM-Newton lightcurve of the event already shown in Fig. 7 and highlight with a red color the data points in the plot that correspond to the physical scenario described in the picture. From top left to bottom right: a) at the beginning of the XMM-Newton observation the NS is accreting from a low density material, such that the observed X-ray luminosity is relatively low (~4    ×    10³² erg s^-1); b) the NS encounters the clump and XMM-Newton observes a rapid rise in the X-ray flux from the source; c) the higher X-ray luminosity (~4    ×    10³⁵ erg s^-1) causes the photoionization of the surrounding material and a decrease in N_H; d) accretion decreases and the source undergoes a rapid decay in the X-ray flux; e) the remains of the clump move in front of the NS along the observer line of sight and obscure the X-ray source; f) the remains of the clump move away and the source returns to its quiescent state (~10³² erg s^-1, some residual accretion might still take place).