All Figures

$\begin{figure} \par\includegraphics[width=7.7cm,clip]{4632fig1.ps} \end{figure}$ Figure 1: The background subtracted photon count distribution for our XMM-Newton/SDSS data (dashed histogram) and the CDF-S survey (solid histogram).
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig2.ps}\end{figure}$ Figure 2: The redshift distribution of our XMM-Newton/SDSS survey sample comprising 153 sources (shaded histogram), including the 26 optically unidentified sources, arbitrarily placed in the 1.0-1.5 redshift bin (see text). We also plot the redshift distribution of the 44 sources from the HELLAS2XMM survey (Perola et al. 2004, open histogram), normalized to our data.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig3.ps} \end{figure}$ Figure 3: The 2-8 keV intrinsic luminosity versus redshift plot for the XMM-Newton (open circles) and the Chandra (filled triangles) sources.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.6cm,clip]{4632fig4.ps} \end{figure}$ Figure 4: The $N_{\rm H}$ distribution of the sources in the combined XMM-Newton sample (solid line) compared to that derived from the CDF-S observations (dashed line).
Open with DEXTER

In the text

$\begin{figure} \par\hspace*{2mm} \includegraphics[height=5.95cm,width=6.2cm,clip... ...{3mm} \includegraphics[height=5.95cm,width=6cm,clip]{4632fg5c.eps} \end{figure}$ Figure 5: The fraction of obscured ( $N_{\rm H}>10^{22}$ cm^-2) sources presented in the XMM-Newton data ( upper panel) and the Chandra data ( middle panel), as a function of the 2-8 keV, intrinsic luminosity. In the lower panel we plot the same fraction for the combined XMM-Newton and Chandra samples. In this panel, we also plot our best-fit model and these of Ueda et al. (2003) and La Franca et al. (2005).
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig6.ps} \end{figure}$ Figure 6: The observed fraction of obscured AGN as a function of redshift. The solid line gives the expected fraction, assuming the luminosity function of Ueda et al. (2003) combined with our best fit model relation between the obscured fraction of AGN and luminosity. The dotted-dashed line gives the expected fraction, assuming no dependence of F on luminosity for a ratio of obscured to unobscured AGN R=1. The long dashed line shows the input distribution of the fraction of obscured sources used in our simulations (see Appendix A), and the short dashed line the resulting one after fitting the simulated spectra.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig7.ps} \end{figure}$ Figure 7: The space density of the CDF-S AGN as a function of redshift in four luminosity ranges, Log $L_{\rm X}$ = 42-43, Log $L_{\rm X}$ = 43-44, Log $L_{\rm X}$ = 44-44.5, and Log $L_{\rm X}$ = 44.5-45.5. The errors correspond to the 1 $\sigma$ confidence level.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig8.ps} \end{figure}$ Figure 8: The fraction of the sources with $N_{\rm H}>10^{22}$ cm^-2 for the XMM-Newton sample (open circles) and the Chandra sample (filled circles). The triangles represent the EGS Chandra survey of Georgakakis et al. (2006b). The solid line gives the predicted fraction using the $F-L_{\rm X}$ relation derived here. The long and short dashed lines give the models with R=4 and R=1 ratios of obscured to unobscured AGN, respectively, with no dependence on luminosity.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig9.ps} \end{figure}$ Figure A.1: This plot summarizes the results of the performed simulations concerning the validity of the spectral analysis of the CDF-S data. The solid line histogram describes the initial $N_{\rm H}$ distribution of all sources, and the short dashed line the corresponding one, after fitting the faked data in XSPEC. Similarly, the dotted and the long dashed histograms show the same results, using only the low z (z<1) data.

In the text

$\begin{figure} \par\includegraphics[width=7.7cm,clip]{4632fig1.ps} \end{figure}$	Figure 1: The background subtracted photon count distribution for our XMM-Newton/SDSS data (dashed histogram) and the CDF-S survey (solid histogram).
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig2.ps}\end{figure}$	Figure 2: The redshift distribution of our XMM-Newton/SDSS survey sample comprising 153 sources (shaded histogram), including the 26 optically unidentified sources, arbitrarily placed in the 1.0-1.5 redshift bin (see text). We also plot the redshift distribution of the 44 sources from the HELLAS2XMM survey (Perola et al. 2004, open histogram), normalized to our data.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig3.ps} \end{figure}$	Figure 3: The 2-8 keV intrinsic luminosity versus redshift plot for the XMM-Newton (open circles) and the Chandra (filled triangles) sources.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.6cm,clip]{4632fig4.ps} \end{figure}$	Figure 4: The $N_{\rm H}$ distribution of the sources in the combined XMM-Newton sample (solid line) compared to that derived from the CDF-S observations (dashed line).
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.5cm,clip]{4632fig7.ps} \end{figure}$	Figure 7: The space density of the CDF-S AGN as a function of redshift in four luminosity ranges, Log $L_{\rm X}$ = 42-43, Log $L_{\rm X}$ = 43-44, Log $L_{\rm X}$ = 44-44.5, and Log $L_{\rm X}$ = 44.5-45.5. The errors correspond to the 1 $\sigma$ confidence level.
Open with DEXTER