\begin{table}
\begin{table}%t6
\caption{\label{tab:lxlbol}X-ray emission observed in  Herbig Ae stars and debris disk stars.
}
%\centerline
 {\begin{tabular}{lrr@{}lr}
\hline
\hline
%HD                 log Lx       Instr. + Reference     LogLbol      Reference  Log Lx/Lbol
\multicolumn{1}{c}{Object \rule{0pt}{2.6ex}} &
\multicolumn{1}{c}{log $L_{\rm X}$} &
\multicolumn{2}{c}{Instrument} &
%\multicolumn{1}{c}{log $L_{\rm bol}$} &
\multicolumn{1}{c}{log ($L_{\rm X}/L_{\rm bol}$)} \\
\multicolumn{1}{c}{name} &
\multicolumn{1}{c}{[erg/s]} &
&
&
%\multicolumn{1}{c}{[erg/s]} &
\\
\hline
HD~97048    &       29.58 & {\it  XMM}     & $^{a}$   & $-$5.64 \\
HD~97300    &       29.31 & {\it  Chandra} & $^{b}$   & $-$5.81 \\
HD~100453   &       28.82 & {\it  Chandra} & $^{c}$   & $-$5.66 \\
HD~100546   &       28.93 & {\it  Chandra} & $^{b}$   & $-$6.16 \\
HD~135344B  & $\sim$29.6  & {\it  ROSAT}   & $^{d}$   & $\sim$$-$4.89 \\
HD~144432   &       28.9  & {\it  Chandra} & $^{e}$   & $-$5.69 \\
HD~144668    &       28.3 & {\it  Chandra} & $^{e}$   & $-$7.22 \\
HD~150193   &       29.32 & {\it  Chandra} & $^{b}$   & $-$5.64 \\
HD~152404   &       29.09 & {\it  Chandra} & $^{b}$   & $-$5.44 \\
HD~158643   &    $<$28.98 & {\it  ROSAT}   & $^{f}$   & $<$$-$6.99 \\
HD~163296   &       29.6  & {\it  Chandra} & $^{b,g}$ & $-$5.36 \\
HD~169142   &       29.08 & {\it  Chandra} & $^{h}$   & $-$5.66 \\
HD~176386   &    $<$28.56 & {\it  Chandra} & $^{b}$   & $<$$-$6.71 \\
\hline
HD~39060   &       26.5  & {\it  Chandra} & $^{i}$    & $-$8.03 \\
HR~109573    &       29.4  & {\it  ROSAT}   & $^{j}$  & $-$5.50 \\
HD~172555   &    $<$26.9  & {\it  Chandra} & $^{k}$   & $<$$-$7.64 \\
HD~181327   &    $<$29.4  & {\it  ROSAT}   & $^{j}$   & $<$$-$4.72 \\
\hline 
V380~Ori    &       30.96 & {\it  Chandra} & $^{b}$   & $-$4.66 \\
BF~Ori      &    $<$30.2  & {\it  ROSAT}   & $^{l}$   & $<$$-$4.91 \\
%HD~97048    &       29.58 & XMM     & $^{a}$   & 35.22 & $-$5.64 \\
%HD~97300    &       29.31 & Chandra & $^{b}$   & 35.12 & $-$5.81 \\
%HD~100453   &       28.82 & Chandra & $^{c}$   & 34.48 & $-$5.66 \\
%HD~100546   &       28.93 & Chandra & $^{b}$   & 35.09 & $-$6.16 \\
%HD~135344B  & $\sim$29.6  & ROSAT   & $^{d}$   & 34.49 & $\sim$$-$4.89 \\
%HD~144432   &       28.9  & Chandra & $^{e}$   & 34.59 & $-$5.69 \\
%HD~144668    &       28.3 & Chandra & $^{e}$   & 35.52 & $-$7.22 \\
%HD~150193   &       29.32 & Chandra & $^{b}$   & 34.96 & $-$5.64 \\
%HD~152404   &       29.09 & Chandra & $^{b}$   & 34.53 & $-$5.44 \\
%HD~158643   &    $<$28.98 & ROSAT   & $^{f}$   & 35.97 & $<$$-$6.99 \\
%HD~163296   &       29.6  & Chandra & $^{b,g}$ & 34.96 & $-$5.36 \\
%HD~169142   &       29.08 & Chandra & $^{h}$   & 34.74 & $-$5.66 \\
%HD~176386   &    $<$28.56 & Chandra & $^{b}$   & 35.27 & $<$$-$6.71 \\
%\hline
%HD~39060   &       26.5  & Chandra & $^{i}$    & 34.53 & $-$8.03 \\
%HR~109573    &       29.4  & ROSAT   & $^{j}$  & 34.90 & $-$5.50 \\
%HD~172555   &    $<$26.9  & Chandra & $^{k}$   & 34.54 & $<$$-$7.64 \\
%HD~181327   &    $<$29.4  & ROSAT   & $^{j}$   & 34.12 & $<$$-$4.72 \\
%\hline 
%V380~Ori    &       30.96 & Chandra & $^{b}$   & 35.62 & $-$4.66 \\
%BF~Ori      &    $<$30.2  & ROSAT   & $^{l}$   & 35.11 & $<$$-$4.91 \\
\hline
\end{tabular}}
\par
\smallskip
Notes:
The log~$L_{\rm X}$ values have been collected from the literature, while
the log~$L_{\rm bol}$ are from Table~\ref{tab:targetvals}.\\
References:
%$_X$XMM,
%$_C$Chandra,
%$_R$ROSAT,
$^a$ Stelzer et~al.\ (\cite{Stelzer2004}),
$^b$ Stelzer et~al.\ (\cite{Stelzer2006}),
$^c$ Collins et~al.\ (\cite{Collins2009}),
$^d$ Grady et~al.\ ApJ, {\sl submitted},
$^e$ Stelzer et~al.\ (\cite{Stelzer2008}),
$^f$ Berghoefer et~al.\ (\cite{Berghoefer1996}),
$^g$ Swartz et~al.\ (\cite{Swartz2005}),
$^h$ Grady et~al.\ (\cite{Grady2007}),
$^i$ Robrade, priv.\ comm.
%Hempel et~al.\ (\cite{Hempel2005}),				%(=Robrade,priv.comm)
$^j$ Stelzer \& Neuh\"auser (\cite{StelzerNeuhaeuser2000}),
$^k$ Feigelson et~al.\ (\cite{Feigelson2006}), and
$^l$ Hamaguchi et~al.\ (\cite{Hamaguchi2005}).
\end{table}