All Figures

$\begin{figure} \par\begin{tabular}{\vert c\vert c\vert c\vert} \hline DSS & $H$... ...graphics[width=0.1\textheight]{7617fig14.ps}\\ \hline \end{tabular}\end{figure}$ Figure 1: From left to right, we show the morphology of the Sculptor group targets in the optical (DSS), infrared H (SOFI), and a false-color montage of H $\alpha$ and R (EFOSC2) images. The reddish, diffuse nebulae in the right image are H II regions, and the vertical ticks mark those for which spectra have been obtained. The galaxy luminosity decreases from top to bottom panels, with the exception of ESO 294 G010, which was not observed in the NIR. In all images, North is up and East to the left, and the field of view is $\sim$ $5\hbox {$^\prime $ }$ $\times$ $5\hbox {$^\prime $ }$ .
Open with DEXTER

In the text

$\begin{figure} \par\begin{tabular}{\vert c\vert c\vert c\vert} \hline DSS & $H$... ...graphics[width=0.1\textheight]{7617fig24.ps}\\ \hline \end{tabular}\end{figure}$ Figure 1: continued.
Open with DEXTER

In the text

$\begin{figure} \par\begin{tabular}{\vert c\vert c\vert} \hline DSS & $H$\\ \hl... ...graphics[width=0.1\textheight]{7617fig32.ps}\\ \hline \end{tabular}\end{figure}$ Figure 2: The NIR, H-band, morphology of the M 81 group dIrrs observed at WHT with INGRID ( right column) is compared to their optical appearance as seen in DSS images ( left column). The galaxy luminosity decreases from top to bottom panels. In all images, North is up and East to the left, and the field of view is $\sim$ $6\hbox {$^\prime $ }$ $\times$ $6\hbox {$^\prime $ }$ in the left column and $\sim$ $5\hbox {$^\prime $ }$ $\times$ $5\hbox {$^\prime $ }$ in the right column.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{7617fig33.ps}\end{figure}$ Figure 3: For each dIrr in the Sculptor group sample we show the spectrum of one of the H II regions that enter the L-Z relation. The spectra are masked near the strong night sky line [O I] $\lambda 5579$ , which leads to poor sky subtraction. The reddest, noisiest, part of the spectrum is omitted for two objects. For display purposes, each flux has been multiplied by 10¹⁵ and a constant has been added.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{7617fig34.ps}\end{figure}$ Figure 4: For three galaxies in the M 81 group sample the spectrum of the target H II region is shown, with a label identifying the host galaxy. The spectra of other galaxies are of poor quality and have not been used for abundance determinations. For display purposes, each flux has been multiplied by 10¹⁵ and a constant has been added.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{7617fig35.ps}\end{figure}$ Figure 5: Comparison of our abundance determinations to literature values, for H II regions in galaxies with independent - and direct - determinations of $12+\log{\rm (O/H)}$ . The dotted line marks the median deviation of -0.1 dex. The galaxy name is followed by the reference acronym, and its subscript is the region number in the reference paper.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.2cm,clip]{7617fig36.ps}\end{figure}$ Figure 6: Metallicity of H II regions vs. absolute H luminosity of galaxies in the Sculptor and M 81 groups. The upper panel shows all direct oxygen measurements listed in Table 7, while in the lower panel only selected regions are plotted with filled diamonds (see text). The dashed line is a weighted least-squares fit to the data, and the dotted lines feature the $\pm 1\sigma$ dispersion around the fit. The galaxy IDs in the upper panel are followed by the acronym of the paper where the abundances have been published (see Table 7), and the subscript is the region number in that paper. To separate the labels, small random vertical offsets have been introduced. The open circles at $M_{H}\sim -15.5$ represent the two components of I Zw 18 for the two distances listed in Table 7, while the open square represents SBS 0335-052.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8.4cm,clip]{7617fig37.ps}\end{figure}$ Figure 7: Comparison of the luminosities and abundances of our fiducial galaxies (filled diamonds) with the predictions of a set of closed-box models of increasing total masses (dotted line curves). For each model the evolution has been truncated when the remaining gas mass drops below 3 $\times$ $10^{7}~\mathcal{M}_{\odot}$ , and the sequence of the end-points is outlined by the solid curve. The open symbols are the same as in Fig. 6.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=8cm,clip]{7617fig38.ps}\end{figure}$ Figure 8: Abundance vs. absolute H luminosity for galaxies with data taken from the literature (filled triangles) and for our targets (filled circles). In the upper panel, the dashed line is an unweighted fit to the literature data, while our fiducial relation is shown in the lower panel. In both panels dotted lines outline the rms dispersion around the fit.
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=12cm,clip]{7617fig39.ps}\end{figure}$ Figure 9: Oxygen abundances vs. H luminosity for the Salzer et al. (2005) emission-line galaxies (KBG calibration), our dIrrs, and data compiled from the literature. In all panels the dashed line is the fit obtained by Salzer et al. to their data points (small open circles). In the top panel, the thin solid line is the same curve as that shown in Fig. 7, while the filled triangles and solid line correspond to our fiducial L-Z relation. In the central panel, the dotted line is a weighted fit to Salzer et al. galaxies fainter than M_H=-20, while the filled triangles and solid line relate to our L-Z relation obtained using abundances re-computed by us with the empirical, indirect method. In the bottom panel, we show the L-Z relation from literature data (filled triangles and solid line).
Open with DEXTER

In the text

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{7617fig40.ps}\end{figure}$ Figure B.1: Response functions for each date of the Lick run: the solid curves are the functions for the blue and red spectra, the dashed curve is the full spectrum function (no dichroic), and the dotted lines are the functions for the high resolution spectra. The functions have been normalized to the peak response.
Open with DEXTER

In the text

$\begin{figure} \par\begin{tabular}{\vert c\vert c\vert c\vert} \hline DSS & $H$... ...graphics[width=0.1\textheight]{7617fig24.ps}\\ \hline \end{tabular}\end{figure}$	Figure 1: continued.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{7617fig34.ps}\end{figure}$	Figure 4: For three galaxies in the M 81 group sample the spectrum of the target H II region is shown, with a label identifying the host galaxy. The spectra of other galaxies are of poor quality and have not been used for abundance determinations. For display purposes, each flux has been multiplied by 10¹⁵ and a constant has been added.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{7617fig35.ps}\end{figure}$	Figure 5: Comparison of our abundance determinations to literature values, for H II regions in galaxies with independent - and direct - determinations of $12+\log{\rm (O/H)}$ . The dotted line marks the median deviation of -0.1 dex. The galaxy name is followed by the reference acronym, and its subscript is the region number in the reference paper.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=8cm,clip]{7617fig38.ps}\end{figure}$	Figure 8: Abundance vs. absolute H luminosity for galaxies with data taken from the literature (filled triangles) and for our targets (filled circles). In the upper panel, the dashed line is an unweighted fit to the literature data, while our fiducial relation is shown in the lower panel. In both panels dotted lines outline the rms dispersion around the fit.
Open with DEXTER

$\begin{figure} \par\includegraphics[width=7.8cm,clip]{7617fig40.ps}\end{figure}$	Figure B.1: Response functions for each date of the Lick run: the solid curves are the functions for the blue and red spectra, the dashed curve is the full spectrum function (no dichroic), and the dotted lines are the functions for the high resolution spectra. The functions have been normalized to the peak response.
Open with DEXTER