0.5–7 keV light curves for each FXT candidate: (1st column) full exposure, in units of counts; (2nd column) zoom in, from the detection of first photon to the end of the exposure, in units of count rate (cts s⁻¹), with log-log scaling and 5 counts per bin. The gray dashed lines show the stop-time per observation regarding the beginning of the transient; (3rd column) long-term light curve, with each point representing individual Chandra exposures (cyan circles with 1-σ error bars) to highlight the significance of detections and nondetections, in units of counts; (4th column) long-term light curve, with each point representing individual Chandra (cyan), XMM-Newton (orange) and Swift-XRT (green) exposures in units of flux (erg s⁻¹ cm⁻²). For the long-term light curves, the observation including the transient is denoted by a large red star (1-σ error bars), while triangles denote observations with (3-σ) upper limits. All fluxes are reported in the 0.5–7 keV band in the observer’s frame.