\begin{table}%t1 \caption{\label{tab:rellx}$h(z)^{-2/3}Y_{\rm sph}(\Rv) - h(z)^{-7/3}\LX$ and updated $h(z)^{-7/3}\LX - \Mv$~relations (see~text).} %\centering \par \begin{tabular}{lcccc} \hline \hline \noalign{\smallskip} Relation & $\log_{10} C $ & $\alpha$ & $\sigma_{\rm log,i}$ \\ \hline $Y_{\rm sph}(\Rv) - \LX - {\rm MB}$ & $-4.940 \pm 0.036$ &$1.07 \pm 0.08$ & $0.190\pm0.025$ \\ $\LX - \Mv - {\rm MB}$ & $0.193 \pm 0.034$ &$1.76 \pm 0.13$ & $0.199\pm0.035$ \\ $Y_{\rm sph}(\Rv) - \LX$ & $-5.047 \pm 0.037$ &$1.14 \pm 0.08$ & $0.184\pm0.024$ \\ $\LX - \Mv$ & $0.274 \pm 0.032$ &$1.64 \pm 0.12$ & $0.183\pm0.032$ \\ \hline \end{tabular} \tablefoot {$\LX$ is the $[0.1{-}2.4]~\keV$ luminosity within $\Rv$. MB: relations corrected for Malmquist bias. For each observable set,~$(B,A)$, we fitted a power law relation of the form $B = C(A/A_0)^\alpha$, with $A_0 = 10^{44}~{h_{70}^{-2}}$~ergs/s and $3$~$\times$ $10^{14}~{h_{70}^{-1}}~\msol$ for $\LX$ and~$\Mv$, respectively. $\sigma_{\rm log,i}$:~intrinsic scatter about the best fitting relation in the $\log {-} \log$~plane.} \vspace*{5mm} \end{table}