Bubble X-ray luminosities L_x versus bubble radius R₂ of the sequences WR100V05 (right, solid) and WR100V05x5.5 (left, dashed) and the bubbles of the [WR]-type sample objects of Table 3. Evolution occurs from left to right, and maximum stellar temperatures are indicated by a vertical mark. Evaporating bubble models are connected by a thick solid or dashed line. The WR100V05 bubbles also contain the information on the luminosity contributions of the hydrogen-poor WR part (crosses) and the evaporated hydrogen-rich PN part (triangles). The arrow indicates the (estimated) shift of the WR100V05 bubbles if the evolutionary timescale is increased by a factor of 2.5. The top panel displays the NEI, the bottom panel the CIE case.