Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[width=15.6cm,clip]{aa3298f1.eps} \end{figure}$ Figure 1: H I Ly $\alpha$ absorptions in the normalized UVES spectra of the QSOs studied here. The top panel shows the Ly $\alpha$ of the $z_{\rm abs}$ = 1.918 DLA system towards HE 0940-1050 with local continuum determined from a full fit to the Lyman series of the $z_{\rm abs}$ = 917 LLS (Levshakov et al. 2003b). For the $z_{\rm abs}$ = 2.476 DLA system towards QSO 0841+129, the Ly $\beta$ absorption is also shown. Smooth lines are the synthetic spectra obtained from the fit giving the N(H I) column densities presented in Tables 3 to 7.
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In the text

$\begin{figure} \par\includegraphics[width=18cm,clip]{aa3298f2.eps} \end{figure}$ Figure 2: Normalized portions of the final spectrum of PKS 0528-250, showing the metal absorptions associated with $z_{\rm abs}$ = 2.141 DLA system. The zero velocity corresponds to $z_{\rm abs}$ = 2.1410, for the N I multiplet we centered on the 1134.4 Å transition. Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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In the text

$\begin{figure} \par\includegraphics[width=11.5cm,clip]{aa3298f8.eps} \end{figure}$ Figure 8: Upper panel: [N/ $\alpha$ ] versus metallicity in DLAs (different big symbols correspond to different $\alpha$ -elements, see figure and Table 9 for references) and in metal-poor H II regions of dwarf galaxies (small dots, see text for references). Bold octagons indicate the new DLA measurements presented here. The measurements in BCD galaxies by Izotov & Thuan (1999) are indicated by black dots, while the remaining data by grey dots. Dotted lines are empirical representations of the secondary and primary N production. In this panel, the horizontal line (primary) is plotted at the mean value of [N/O] in BCD galaxies. The solar level is also indicated (dashed line). Lower panel: same as above but using only the $\alpha$ -element silicon in DLAs, and their mean [N/Si] to represent the primary N production (horizontal dotted line).
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In the text

$\begin{figure} \par\includegraphics[width=12cm,clip]{aa3298f9.eps} \end{figure}$ Figure 9: Upper panel: [N/ $\alpha$ ] vs. N abundance in DLAs (different symbols correspond to different $\alpha$ -elements, see figure and Table 9 for references). Bold octagons indicate the new DLA measurements presented here. Lower panel: same as above but using only the $\alpha$ -element silicon.
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In the text

$\begin{figure} \par\includegraphics[width=12cm,clip]{aa3298f10.eps} \end{figure}$ Figure 10: [N/Si] is plotted versus [Si/Zn] which is only available for DLAs with high-N values (squares). For DLAs with low-N, labelled in the figure, we plot in abscissa [Si/Fe] ratios since none of these systems have determinations of Zn abundance. The low-N system towards QXO0001 has been excluded from the plot since it has a very poor restrictive lower limit $\rm [Si/Fe] >-0.7$ .
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In the text

$\begin{figure} \par\includegraphics[width=16cm,clip]{aa3298f3.eps} \end{figure}$ Figure 3: Normalized portions of the final spectrum of PKS 0528-250, showing the metal absorptions associated with $z_{\rm abs}$ = 2.8120 DLA system (zero velocity). Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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In the text

$\begin{figure} \par\includegraphics[width=16cm,clip]{aa3298f4.eps} \end{figure}$ Figure 4: Normalized portions of the final spectrum of Q0841+126, showing the metal absorptions associated with $z_{\rm abs}$ = 2.3745 DLA system. The zero velocity has been taken in correspondence with $z_{\rm abs}$ = 2.37450, for N I multiplets we centered on the 1134.4 and the 1200.2 Å transitions. Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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In the text

$\begin{figure} \par\includegraphics[width=10cm,clip]{aa3298f5.eps} \end{figure}$ Figure 5: Normalized portions of the final spectrum of Q0841+126, showing the metal absorptions associated with $z_{\rm abs}$ = 2.4762 DLA system (zero velocity), for N I multiplets we centered on the 1134.4 and the 1200.2 Å transitions. Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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In the text

$\begin{figure} \par\includegraphics[width=13cm,clip]{aa3298f6.eps} \end{figure}$ Figure 6: Normalized portions of the final spectrum of HE 0940-1050, showing the metal absorptions associated with $z_{\rm abs}$ = 1.9184 DLA system (zero velocity). Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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In the text

$\begin{figure} \par\includegraphics[width=16cm,clip]{aa3298f7.eps} \end{figure}$ Figure 7: Normalized portions of the final spectrum of Q1232+0815, showing the metal absorptions associated with $z_{\rm abs}$ = 2.337 DLA system. The zero velocity corresponds to $z_{\rm abs}$ = 2.337722, for N I multiplets we centered on the 1134.4 and the 1200.2 Å transitions Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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In the text

$\begin{figure} \par\includegraphics[width=18cm,clip]{aa3298f2.eps} \end{figure}$	Figure 2: Normalized portions of the final spectrum of PKS 0528-250, showing the metal absorptions associated with $z_{\rm abs}$ = 2.141 DLA system. The zero velocity corresponds to $z_{\rm abs}$ = 2.1410, for the N I multiplet we centered on the 1134.4 Å transition. Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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$\begin{figure} \par\includegraphics[width=12cm,clip]{aa3298f9.eps} \end{figure}$	Figure 9: Upper panel: [N/ $\alpha$ ] vs. N abundance in DLAs (different symbols correspond to different $\alpha$ -elements, see figure and Table 9 for references). Bold octagons indicate the new DLA measurements presented here. Lower panel: same as above but using only the $\alpha$ -element silicon.
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$\begin{figure} \par\includegraphics[width=12cm,clip]{aa3298f10.eps} \end{figure}$	Figure 10: [N/Si] is plotted versus [Si/Zn] which is only available for DLAs with high-N values (squares). For DLAs with low-N, labelled in the figure, we plot in abscissa [Si/Fe] ratios since none of these systems have determinations of Zn abundance. The low-N system towards QXO0001 has been excluded from the plot since it has a very poor restrictive lower limit $\rm [Si/Fe] >-0.7$ .
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$\begin{figure} \par\includegraphics[width=16cm,clip]{aa3298f3.eps} \end{figure}$	Figure 3: Normalized portions of the final spectrum of PKS 0528-250, showing the metal absorptions associated with $z_{\rm abs}$ = 2.8120 DLA system (zero velocity). Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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$\begin{figure} \par\includegraphics[width=16cm,clip]{aa3298f4.eps} \end{figure}$	Figure 4: Normalized portions of the final spectrum of Q0841+126, showing the metal absorptions associated with $z_{\rm abs}$ = 2.3745 DLA system. The zero velocity has been taken in correspondence with $z_{\rm abs}$ = 2.37450, for N I multiplets we centered on the 1134.4 and the 1200.2 Å transitions. Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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$\begin{figure} \par\includegraphics[width=10cm,clip]{aa3298f5.eps} \end{figure}$	Figure 5: Normalized portions of the final spectrum of Q0841+126, showing the metal absorptions associated with $z_{\rm abs}$ = 2.4762 DLA system (zero velocity), for N I multiplets we centered on the 1134.4 and the 1200.2 Å transitions. Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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$\begin{figure} \par\includegraphics[width=13cm,clip]{aa3298f6.eps} \end{figure}$	Figure 6: Normalized portions of the final spectrum of HE 0940-1050, showing the metal absorptions associated with $z_{\rm abs}$ = 1.9184 DLA system (zero velocity). Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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$\begin{figure} \par\includegraphics[width=16cm,clip]{aa3298f7.eps} \end{figure}$	Figure 7: Normalized portions of the final spectrum of Q1232+0815, showing the metal absorptions associated with $z_{\rm abs}$ = 2.337 DLA system. The zero velocity corresponds to $z_{\rm abs}$ = 2.337722, for N I multiplets we centered on the 1134.4 and the 1200.2 Å transitions Smooth lines are the synthetic spectra obtained from the fit as described in the text.
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