Free Access
Volume 531, July 2011
Article Number L1
Number of page(s) 6
Section Letters
Published online 30 May 2011

Online material

Appendix A: Gauss fit of data

The data are fitted by Gaussians, with the exception of the narrow absorption component. Figure A.1 shows the example of the H2O 111–000 line, with the residual plotted below. Furthermore, Fig. A.1 shows the CO 3–2 line scaled and overplotted on the H2O 111–000 line, highlighting the similar line profile in the EHV components.

thumbnail Fig. A.1

Top: Gauss fit of the H2O 111–000 line (red) with the residual shown below (offset at  − 0.1 K). The central absorption feature is not fitted. Bottom: CO 3–2 scaled to the peak intensity of H2O in the bullets and overplotted on the H2O 111–000 line.

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Appendix B: RADEX results

The non-LTE, escape-probability code RADEX was used to create rotational diagrams for H2O and CO in the optically thin limit. Collisional rate coefficients are from Faure et al. (2007) and Yang et al. (2010), respectively. The same transitions as observed were then used to calculate the rotational temperature as function of Tkin and nH. The results are shown in Fig. B.1.

RADEX was also used to calculate the optical depth, τ of the HO 110–101 line at 557 GHz. Results are shown in Fig. B.2, where also the beam-filling factor is shown as a function of H2O column density for the three different models.

thumbnail Fig. B.1

Trot of optically thin H2O emission (top), optically thick H2O emission (N = 1017 cm-2; middle) and optically thin CO emission (bottom) determined from RADEX simulations. Trot is calculated from the same transitions as in Sect. 2, i.e., excluding the ground-state transitions. The gray area indicates the observed values of Trot. The points indicate the different physical conditions examined; model 1 (red) has (T, n) = (150 K, 106 cm-3) for the EHV components and (100 K, 106 cm-3) for the broad component. Model 2 (blue) has (T, n) = (500 K, 105 cm-3) for the EHV components, respectively. Model 3 (green) has (T, n) = (500 K, 106 cm-3) for all components.

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thumbnail Fig. B.2

Top: τ of the HO 110–101 line. The black dashed line corresponds to the observed value in each of the three velocity components as specified in Sect. 2. Bottom: beam-filling factor for the three different components and three different models as a function of total H2O column density. Best-fit results are marked with points in both plots.

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Table 2

H2O, HO and CO emission in each velocity component at the source positiona.

Table 3

H2O, HO and CO transitions observed with Herschel-HIFIa.

© ESO, 2011

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