Astronomy & Astrophysics

All Figures

$\begin{figure} \par\includegraphics[width=16cm,clip]{0598fig1.eps} \end{figure}$ Figure 1: The FUSE spectra of HD 100546 (recorded in 2002) and the two other B-stars used as a reference for the photospheric spectrum analysis. For clarity, the spectra plotted in this figure have been rebinned by 40 pixels. In the HD 100546 spectrum, the main emission features are indicated and the brightest airglow lines are labelled with the $\oplus$ symbol. The prominent absorption features between 1110 and 1160 Å are photospheric C I lines.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig2.eps}} \end{figure}$ Figure 2: Comparison of HD 100546 spectra recorded two years apart (2000 - solid line; 2002 - dotted line), in the spectral range of the N I triplet lines. The neighboring CS lines are labeled. Note the variations in the flux level, while the expected stellar continuum level in 2000 is close to the 2002 level. This indicates that extra-absorption occurred in the 2000 spectrum, longward and shortward of the stellar rest velocity.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig3.eps}} \end{figure}$ Figure 3: The 1100 to 1132 Å spectral range for HD 100546 observed in 2000 (solid line), HD 27638 (dotted line) and HD 150100 (dashed line). The flux of the two reference stars has been scaled to HD 100546 at about 1120 Å and co-aligned. All three spectra have been rebinned by 10 pixels for this plot. The main C I blends are labeled at the top.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig4.eps}} \end{figure}$ Figure 4: Spectral variations in Ar I resonance doublet lines at a) 1066.6 Å and b) 1048.2 Å. The top panels show the data recorded in 2000 (solid line) and in 2002 (dotted line). The 2000 spectrum divided by the 2002 one is shown in the bottom panels. The velocity scale is in the rest frame of the star.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig5.eps}} \end{figure}$ Figure 5: Long-term variations of N I observed in the HD 100546 FUSE spectra. The division of the 2000 spectrum by the 2002 one in the LiF 2a channel, rebinned by 4 pixels, is plotted in the spectral range of the various N I lines on velocity scale. The full vertical lines indicate the position of other nearby N I lines.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig6.eps}} \end{figure}$ Figure 6: Long-timescale variations of N II in the HD 100546 FUSE spectra. The spectra from the SiC 1a channel, rebinned by 7 pixels, observed in 2000 (solid line) and in 2002 (dotted line) are shown at the top. The 2000 spectrum divided by the 2002 one is shown at the bottom. The position of the strongest lines of the multiplet in the stellar rest frame are indicated.
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In the text

$\begin{figure} \par\resizebox{7.8cm}{!}{\includegraphics[clip]{0598fig7.eps}} \end{figure}$ Figure 7: Spectral variations in the O I (¹D) line at 1152.15 Å in the LiF 2a segment (solid line: 2000 spectrum; dotted line: 2002 spectrum). Nearby circumstellar absorption lines are indicated.
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In the text

$\begin{figure} \par\resizebox{7.5cm}{!}{\includegraphics[clip]{0598fig8.eps}} \end{figure}$ Figure 8: Same data as in Fig. 7 but in the region around the strongest Fe II line at 1144.9 Å.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig9.eps}} \end{figure}$ Figure 9: Short-timescale variations in HD 100546 FUSE spectra. The first sub-exposure is divided by the second one in the 2000 spectrum ( top) and by the second and the third respectively in 2002 ( middle and bottom). The resulting divided spectra, rebinned by 4 pixels, are plotted in the spectral range of a) the N I triplet and b) the O I (¹D) ${\lambda }$ 1152 line. In both cases, the alignment of the sub-exposures before division can be verified by examination of the ratios in the vicinity of the CS spectral lines.
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In the text

$\begin{figure} \par\resizebox{8.1cm}{!}{\includegraphics[clip]{0598fg10.eps}} \end{figure}$ Figure 10: Emission lines in HD 100546 FUSE spectra (rebinned by 4 pixels), observed on 2000 March 26 (solid line) and 2002 March 3 (dotted line). The airglow line close to the ${\lambda }$ 1037 O VI line is labeled with the $\oplus$ symbol. The narrow unlabeled absorption lines arise from molecular hydrogen.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fg11.eps}} \end{figure}$ Figure 11: O VI ${\lambda }$ 1032, S II ${\lambda }$ 1014 and C III ${\lambda }$ 977 emission lines as observed in the 2002 spectra (rebinned by 4 pixels). The dotted line is the red side of the emission line reflected about zero velocity in the stellar rest frame, highlighting the profile asymmetry.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fg12.eps}} \end{figure}$ Figure 12: Example of line profile decomposition for the ${\lambda }$ 1032 O VI emission line observed in 2000 ( left) and 2002 ( right). The dotted line is the observed profile, rebinned by 4 pixels. The individual fitted components are plotted with dashed lines and the solid line is the resulting profile. Note that we included the H₂ absorption lines in the profile fitting.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fg13.eps}} \end{figure}$ Figure 13: Same as Fig. 12 but for the S II line at 1014 Å.
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In the text

$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig3.eps}} \end{figure}$	Figure 3: The 1100 to 1132 Å spectral range for HD 100546 observed in 2000 (solid line), HD 27638 (dotted line) and HD 150100 (dashed line). The flux of the two reference stars has been scaled to HD 100546 at about 1120 Å and co-aligned. All three spectra have been rebinned by 10 pixels for this plot. The main C I blends are labeled at the top.
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$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig4.eps}} \end{figure}$	Figure 4: Spectral variations in Ar I resonance doublet lines at a) 1066.6 Å and b) 1048.2 Å. The top panels show the data recorded in 2000 (solid line) and in 2002 (dotted line). The 2000 spectrum divided by the 2002 one is shown in the bottom panels. The velocity scale is in the rest frame of the star.
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$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig5.eps}} \end{figure}$	Figure 5: Long-term variations of N I observed in the HD 100546 FUSE spectra. The division of the 2000 spectrum by the 2002 one in the LiF 2a channel, rebinned by 4 pixels, is plotted in the spectral range of the various N I lines on velocity scale. The full vertical lines indicate the position of other nearby N I lines.
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$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fig6.eps}} \end{figure}$	Figure 6: Long-timescale variations of N II in the HD 100546 FUSE spectra. The spectra from the SiC 1a channel, rebinned by 7 pixels, observed in 2000 (solid line) and in 2002 (dotted line) are shown at the top. The 2000 spectrum divided by the 2002 one is shown at the bottom. The position of the strongest lines of the multiplet in the stellar rest frame are indicated.
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$\begin{figure} \par\resizebox{7.8cm}{!}{\includegraphics[clip]{0598fig7.eps}} \end{figure}$	Figure 7: Spectral variations in the O I (¹D) line at 1152.15 Å in the LiF 2a segment (solid line: 2000 spectrum; dotted line: 2002 spectrum). Nearby circumstellar absorption lines are indicated.
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$\begin{figure} \par\resizebox{7.5cm}{!}{\includegraphics[clip]{0598fig8.eps}} \end{figure}$	Figure 8: Same data as in Fig. 7 but in the region around the strongest Fe II line at 1144.9 Å.
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$\begin{figure} \par\resizebox{8.1cm}{!}{\includegraphics[clip]{0598fg10.eps}} \end{figure}$	Figure 10: Emission lines in HD 100546 FUSE spectra (rebinned by 4 pixels), observed on 2000 March 26 (solid line) and 2002 March 3 (dotted line). The airglow line close to the ${\lambda }$ 1037 O VI line is labeled with the $\oplus$ symbol. The narrow unlabeled absorption lines arise from molecular hydrogen.
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$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fg11.eps}} \end{figure}$	Figure 11: O VI ${\lambda }$ 1032, S II ${\lambda }$ 1014 and C III ${\lambda }$ 977 emission lines as observed in the 2002 spectra (rebinned by 4 pixels). The dotted line is the red side of the emission line reflected about zero velocity in the stellar rest frame, highlighting the profile asymmetry.
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$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fg12.eps}} \end{figure}$	Figure 12: Example of line profile decomposition for the ${\lambda }$ 1032 O VI emission line observed in 2000 ( left) and 2002 ( right). The dotted line is the observed profile, rebinned by 4 pixels. The individual fitted components are plotted with dashed lines and the solid line is the resulting profile. Note that we included the H₂ absorption lines in the profile fitting.
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$\begin{figure} \par\resizebox{8.8cm}{!}{\includegraphics[clip]{0598fg13.eps}} \end{figure}$	Figure 13: Same as Fig. 12 but for the S II line at 1014 Å.
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