Fig. 4: Multiwavelength light curves with disk model fit.

a, X-ray, UV and optical data showing the TDE in 2019 (ref. ¹⁶) and the long-term disk emission. The dashed lines and shaded regions show the median and 90% confidence range of our accretion disk model fit²⁵. QPEs (dotted lines) were excluded from the fit. A potential earlier QPE is also seen in the X-ray data at about 800 days (ref. ²¹). Our model is agnostic to the mechanism powering the initial UV/optical peak (Methods) but, by the time of the QPEs, all data are consistent with an exposed accretion disk. b, Radial surface density profiles of the best-fit model at 800 and 1,500 days after disruption (including 90% confidence range). The radius has been normalized to the circular orbit with period T_orb = T_QPE. The vertical lines indicate the orbital radii corresponding to periods of 1× and 2× T_QPE. Both orbits cross the disk plane, showing that star–disk interactions occurring either once or twice per orbit can explain the QPEs in AT2019qiz (ref. ¹¹).