Bolometric luminosity of hot polar cap emission versus rotation period. The lines represent the predicted thermal luminosities in case of curvature radiation (red dashed line) and inverse-Compton scattering (blue dotted line) pair fronts. The theoretical lines are from Harding & Muslimov (2002) in the case of non-recycled pulsars. Pulsars marked with a square are expected to produce pairs only from ICS photons. The error bars on the bolometric luminosity are computed taking into account both the uncertainties of the blackbody fit and those on the distances. See Table 7 for details.