Astronomy & Astrophysics

Table 1: List of emission lines from the Q2233+131 itself and the absorption lines, related to the z = 3.15 DLA system detected in the QSO spectrum. A standard air-to-vacuum correction has been applied to the observed lines before deriving the redshifts. The uncertainties of the measured redshifts are typically $\pm$ 0.0005.
Table 2: Properties of the Ly $\alpha$ emission from different parts of the extended nebula derived from fitting a single Gaussian profile to the observed spectrum. The 1 $\sigma$ errors of the estimations of the Gaussian centroids are 0.5 Å. Note that there is an overlap of the selected spectra belonging to the various regions such that some spectra belonging to the east part also belong to the north (see Fig. 4). The EW is not meaningful to calculate for the different regions, as the continuum emission is restricted to the total emission. Line fluxes listed in Col. 3 have not been corrected for Galactic extinction.
Table 3: The location of the two peaks from fitting simultaneously two Gaussians to the spectra in Fig. 5. The centroids for the fits between the 4 regions vary with <2.5 Å indicating small velocity differences. For all regions the splitting between the two Gaussians are 10-12 Å corresponding to velocities of 600-750 km s^-1. The third column lists the centroid for the absorption line for the fits consisting of an emission line and an absorption line.