2 Observation and data reduction

2.1 Imaging

Figure 1: The F656N HST image of S 119 taken with the PC. The field of view here is $\sim$ $15\hbox{$^{\prime\prime}$ }~\times~15\hbox{$^{\prime\prime}$ }$, and the intensity scaling is logarithmic. A north-east vector indicates the celestial orientation. The filaments described in Sect. 3 are designated as NW-1, NW-2, S-1, and SE-1.

Figure 2: A larger area (30 $^{\prime \prime }$ $\times$ 30 $^{\prime \prime }$) of the same HST image as in Fig. 1 shows the position and orientation of the slits. In addition to the S 119 nebula emission from a closer H II region is visible.

For the morphological analysis we retrieved from the STScI data archive all images of S 119 taken with the HST Planetary Camera (PC) of the Wide Field Planetary Camera 2 using the F656N (H$_\alpha$) filter. The exposure times were 500 s for four images, and 5 and 30 s for two each. The data were reduced with the standard STSDAS/IRAF routines. In total the four 500 s exposures were combined and cosmic-ray cleaned. They were not mosaiced since the nebula is fully covered by the PC field of view. The pixel size in the Planetary Camera is 0.0455 $^{\prime \prime }$ per pixel, the effective resolution about 0 $.\!\!^{\prime\prime}$1. The images were not rotated or binned to make sure to maintain the full resolution. The celestial directions therefore are indicated in the images. The HST system position angle is 148.5$^\circ$. Figure 1 shows a section of $\sim$ $15\hbox{$^{\prime\prime}$ }~\times~15\hbox{$^{\prime\prime}$ }$ from the reduced PC image which we used for the analysis. The almost full field of view of the PC image is shown in Fig. 2.

  
2.2 Long-slit echelle spectroscopy

Figure 3: Echellograms (center column) and corresponding position-velocity diagrams (right column) for the observed slits. Velocity measurements are with respect to the heliocentric system. In the left column an enlargment of the [N  II]$\lambda$6583 Å line is shown.

Figure 4: Echellograms (center column) and corresponding position-velocity diagrams (right column) for the observed slits. Velocity measurements are with respect to the heliocentric system. In the left column an enlargment of the [N  II]$\lambda$6583 Å line is shown.

For the kinematic analysis of the S 119 nebula we obtained high-resolution long-slit echelle spectra with the 4 m-telescope at the Cerro Tololo Inter-American Observatory. For the order selection we replaced the cross-disperser by a flat mirror and inserted a post-slit H$_\alpha$ filter (6563/75 Å). This setup left us with a long-slit vignetted to a length of $\sim$$4^\prime$and a spectral range that contained the H$_\alpha$ line and two [N  II] lines at 6548 Å and 6583 Å. We chose the 79 l mm^-1 echelle grating and a slit-width of 150 $\mu$m (corresponding to 1 $^{\prime \prime }$), which lead to an instrumental FWHM at the H$_\alpha$ line of 8 km s^-1. The data were recorded with the long focus red camera and a $2048~\times~2048$ pixel CCD with a pixel size of 0.08 Å pixel^-1 along the dispersion and 0 $\hbox{$.\!\!^{\prime\prime}$ }$26 pixel^-1 on the spatial axis. Seeing was $\sim$ $1\hbox{$.\!\!^{\prime\prime}$ }2$. Thorium-argon comparison lamp frames were taken for wavelength calibration and geometric distortion correction. Telluric lines visible in the spectra were used to improve the absolute wavelength calibration of which we estimate an accuracy of better than 0.08 Å.

We observed at two different position angles (PA) which were nearly perpendicular to each other. Four slit positions mapped the nebula with a ${\rm PA} = 125\hbox{$^\circ$ }$, one centered on the star (Slit Center), one offset 2 $.\!\!^{\prime\prime}$5 to the north (Slit 2.5N) as well as one each at 2 $.\!\!^{\prime\prime}$5 and 5 $^{\prime \prime }$ to the south (Slits 2.5S and 5S). One additional observation was made with the slit oriented to ${\rm PA} = 213\hbox{$^\circ$ }$ and centered on S 119 (Slit PA = 213). Figure 2 shows the slit positions. Figures 3 and 4 summarize our spectroscopic observations. The center column of Figs. 3 and 4 show the echellograms of each slit position we observed, the right column the corresponding position velocity diagrams (pv-diagrams). The echellograms are 54 Å long and extend 1$^\prime$ in spatial direction, centered on the projected position of the star. The top of the echellograms points towards north-west for ${\rm PA} = 125\hbox{$^\circ$ }$ and towards south-west for ${\rm PA} = 213\hbox{$^\circ$ }$. In each echellogram an insert (of $20\hbox{$^{\prime\prime}$ }~\times~5$ Å) shows the expansion ellipse of the stronger [N  II] line (6583 Å) at a different cut level. The slits are identified according to the nomenclature as introduced above. In the pv-diagrams the positions are given as offsets from the projected location of the star. Offsets to the north-west (or, in the case of Slit PA  =  213, south-west) are counted positive. The velocity measurements for the pv-diagrams followed from the H$_\alpha$ and the stronger [N  II] line at 6583 Å. We estimate an error of the line fits to determine the radial velocities between $\pm$0.5-1 km s^-1, this is well below the printed symbol size in the pv-diagramms. All velocities are with respect to the heliocentric system, unless mentioned otherwise.

  
2.3 ROSAT HRI data

In addition to the optical morphology and the kinematic analysis we looked up ROSAT HRI observations of the S 119 region. The ROSAT satellite was sensitive to X-ray emission between 0.1 and 2.4 keV and its HRI achieves a spatial resolution of $\sim$ $5\hbox{$^{\prime\prime}$ }$. A 21 ks ROSAT pointing was retrieved from the Max-Planck-Institut für Extraterrestrische Physik (MPE) ROSAT data center. After reduction and analysis of the X-ray image with IRAF/PROS, we found no traces of S 119 in the data.