Fig. 3: Comparison between experiment and photon bubble model.

Auto-correlation structure at the transition region, δ = −2Γ (a), and in the turbulent regime, δ = −0.75Γ (b). The blue dashed curve depicts the fit to the spherically symmetric solutions of the homogeneous photon bubble model. The red curve shows the improved fit when finite-size effects are taken into consideration. Both fits were performed only at scales larger than the probed layer thickness, where line-of-sight integration effects become negligible. Error bars have been defined in Fig. 2.