$\begin{figure} \par\includegraphics[width=6.4cm,angle=90,clip=]{7429fig1.ps}\end{figure}$ Figure 1: Number of A-type stars at a given separation between the optical position of the star and the position of the associated X-ray source. The dotted line shows the data for the BSC-RASS correlation, the dashed line represents the BSC-PSPC data and the solid line those from the BSC-HRI correlation.
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In the text

$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig2.ps}\end{figure}$ Figure 2: Percentage of X-ray active stars $N_{\rm x}$ from the total number of stars $N_{\rm BSC}$ of a given spectral type. Note the strong increase in the X-ray detection rates for stars in the range A9-F3.
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In the text

$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig3.ps}\end{figure}$ Figure 3: $L_{\rm x}$ vs. distance for the 312 A-type stars associated with a ROSAT X-ray source. The crosses indicate single stars, and the diamonds known or possible multiple systems. The dotted line represents the typical detection limit for the RASS observations, i.e., $f_{\rm X} \space \approx \space 10^{-13}$ erg cm^-2 s^-1.
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In the text

$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig4.ps}\end{figure}$ Figure 4: Cumulative distribution function of the X-ray luminosity for the single star sample (solid line) and binary star sample (dotted line). The null hypothesis that both samples originate from the same distribution can be rejected with a significance of 95%.
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In the text

$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig5.ps}\end{figure}$ Figure 5: Comparison of X-ray count rates for 35 stars detected both in the all-sky survey and the PSPC pointing program. The two dotted lines indicate a factor 2 variation from unity. Single and double stars are represented by crosses and diamonds respectively. Stars with large deviations from the regression line are identified.
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In the text

$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig6.ps}\end{figure}$ Figure 6: Comparison of X-ray count rates for 14 stars detected both in the PSPC pointing program and the HRI pointing program. The two dotted lines indicate a factor 2 variation from unity. Single and double stars are represented by crosses and diamonds respectively. Stars with large deviations from the regression line are identified.
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In the text

$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig7.ps}\end{figure}$ Figure 7: Comparison of X-ray count rates for 55 stars detected both in the PSPC survey program and the HRI pointing program. The two dotted lines indicate a factor 2 variation from unity. Single and double stars are represented by crosses and diamonds respectively. Stars with large deviations from the regression line are identified.
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In the text

$\begin{figure} \par\includegraphics[width=8.3cm,angle=0,clip=]{7429fig8.ps}\end{figure}$ Figure 8: ROSAT-HRI image of HR 789. The separation between the brighter X-ray source and the optical position of the A-type star is about an arcsecond.
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In the text

$\begin{figure} \par\includegraphics[width=6.4cm,angle=90,clip=]{7429fig1.ps}\end{figure}$	Figure 1: Number of A-type stars at a given separation between the optical position of the star and the position of the associated X-ray source. The dotted line shows the data for the BSC-RASS correlation, the dashed line represents the BSC-PSPC data and the solid line those from the BSC-HRI correlation.
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$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig2.ps}\end{figure}$	Figure 2: Percentage of X-ray active stars $N_{\rm x}$ from the total number of stars $N_{\rm BSC}$ of a given spectral type. Note the strong increase in the X-ray detection rates for stars in the range A9-F3.
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$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig3.ps}\end{figure}$	Figure 3: $L_{\rm x}$ vs. distance for the 312 A-type stars associated with a ROSAT X-ray source. The crosses indicate single stars, and the diamonds known or possible multiple systems. The dotted line represents the typical detection limit for the RASS observations, i.e., $f_{\rm X} \space \approx \space 10^{-13}$ erg cm^-2 s^-1.
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$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig4.ps}\end{figure}$	Figure 4: Cumulative distribution function of the X-ray luminosity for the single star sample (solid line) and binary star sample (dotted line). The null hypothesis that both samples originate from the same distribution can be rejected with a significance of 95%.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig5.ps}\end{figure}$	Figure 5: Comparison of X-ray count rates for 35 stars detected both in the all-sky survey and the PSPC pointing program. The two dotted lines indicate a factor 2 variation from unity. Single and double stars are represented by crosses and diamonds respectively. Stars with large deviations from the regression line are identified.
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$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig6.ps}\end{figure}$	Figure 6: Comparison of X-ray count rates for 14 stars detected both in the PSPC pointing program and the HRI pointing program. The two dotted lines indicate a factor 2 variation from unity. Single and double stars are represented by crosses and diamonds respectively. Stars with large deviations from the regression line are identified.
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$\begin{figure} \par\includegraphics[width=6.5cm,angle=90,clip=]{7429fig7.ps}\end{figure}$	Figure 7: Comparison of X-ray count rates for 55 stars detected both in the PSPC survey program and the HRI pointing program. The two dotted lines indicate a factor 2 variation from unity. Single and double stars are represented by crosses and diamonds respectively. Stars with large deviations from the regression line are identified.
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$\begin{figure} \par\includegraphics[width=8.3cm,angle=0,clip=]{7429fig8.ps}\end{figure}$	Figure 8: ROSAT-HRI image of HR 789. The separation between the brighter X-ray source and the optical position of the A-type star is about an arcsecond.
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