Fits to the broadband light curves of the 13 merger-induced GRB afterglows in the final sample. The upper panel shows the flux density as a function of time since the GRB trigger. Black, blue and green points represent X-ray, optical, and radio detections, respectively; coloured triangles denote true upper limits, while grey triangles represent detections that were treated as upper limits in the fitting procedure as they were deemed to be caused by another emission process than the standard forward shock afterglow emission. Dashed lines mark the best fit (maximum a posteriori) to the data, accompanied by a hundred samples randomly drawn from the posterior flux density distribution within the 16th – 84th percentile range to visualise the uncertainty region. The bottom panel shows the evolution of the photon index of the X-ray spectrum, Γ_X(t), also taken from the Swift Light Curve Repository. For GRB 050709 and GRB 160821B, all X-ray data were taken from other authors rather than from the Swift Light Curve Repository, such that the evolution of the photon index is not shown.