Convergence diagnostics for the HXMT Crab example. For each parameter, the left panel shows the post-warm-up trace for the four chains (distinguished by color), together with a dark-blue smoothed running mean as a visual guide; the middle panel shows the marginal posterior density by chain, and the right panel shows the per-draw deviance cloud. Stable traces, overlapping densities, and the absence of systematic drifts or isolated high-deviance excursions indicate good mixing and convergence.