Free Access
Issue
A&A
Volume 579, July 2015
Article Number A80
Number of page(s) 26
Section Interstellar and circumstellar matter
DOI https://doi.org/10.1051/0004-6361/201423989
Published online 01 July 2015

Online material

Appendix A

Appendix A.1: Molecular column densities

We calculated the molecular column densities of the upper level of a particular transition following the equation for optically thin emission (A.1)where the integrated intensity given in K km s-1, and the Einstein coefficient Aul is in s-1, and with (A.2)where ν is the frequency of the observed transition (e.g., Mangum & Shirley 2015). Then the total column density (which we refer to from now on as column density) can be calculated: (A.3)When we were able derive the optical depth τ from hyperfine splitting, we corrected for the column density using (A.4)

To obtain abundances, we derived H2 column densities either from dust maps obtained with Mambo with the IRAM 30 m telescope at 1.2 mm (Beuther et al. 2002b) which provides a resolution of 11″, or the galactic plane survey ATLASGAL (Schuller et al. 2009) at 870 μm with a resolution of 19.2″, or the SCUBA Legacy Catalog (Di Francesco et al. 2008) at 850 μm with a resolution of 22.9″ (see Table A.1). The continuum data were smoothed to 29″ resolution to be beam-matched with the IRAM 30 m observations at 3 mm and the SMT molecular line data. H2 column densities were calculated from the observed peak intensities assuming optically thin emission and LTE following Eq. (A.5) (Schuller et al. 2009). The dust opacities used were κ850 μm = 1.48, κ870 μm = 1.42, κ1.2 mm = 0.97, interpolated values from Ossenkopf & Henning (1994), assuming grains with thin ice mantles, gas densities of n = 105 cm-3, and a gas-to-dust mass ratio R = 100. With these assumptions the H2 column density is calculated as (A.5)The uncertainties in the derived H2 column densities are mainly based on the dust and temperature properties and are about a factor of 3. A more detailed description of the derivation is given in Gerner et al. (2014).

The molecular column densities are then divided by the H2 column densities, and the averaged abundances are derived.

Table A.1

Source list showing the position, the distance, and the evolutionary stage of all high-mass star-forming regions.

Table A.2

Luminosity, H2, DCO+, DCN, DNC, and N2D+ column density and the corresponding error (Δ) for each source.

Table A.3

HCO+, HCN, HNC, and N2H+ column density and corresponding error (Δ) for each source.

Table A.4

Parameters of the best-fit IRDC model.

Table A.5

Parameters of the best-fit HMPO model.

Table A.6

Parameters of the best-fit HMC model.

Table A.7

Parameters of the best-fit UCHii model.

Table A.8

Median column densities in a(x) = a × 10x for observations (including detections and upper limits) and best-fit IRDC model.

Table A.9

Median column densities in a(x) = a × 10x for observations (including detections and upper limits) and best-fit HMPO model.

Table A.10

Median column densities in a(x) = a × 10x for observations (including detections and upper limits) and best-fit HMC model.

Table A.11

Median column densities in a(x) = a × 10x for observations (including detections and upper limits) and best-fit UCHii model.

thumbnail Fig. A.1

Observed and modeled column densities in cm-2 at the IRDC stage. The observed values are shown in blue, the modeled values in black. The error bars are indicated by the vertical marks. Molecules are labeled in the plots.

Open with DEXTER

thumbnail Fig. A.2

Observed and modeled column densities in cm-2 at the HMPO stage. The observed values are shown in blue, the modeled values in black. The error bars are indicated by the vertical marks. Molecules are labeled in the plots.

Open with DEXTER

thumbnail Fig. A.3

Observed and modeled column densities in cm-2 at the HMC stage. The observed values are shown in blue, the modeled values in black. The error bars are indicated by the vertical marks. Molecules are labeled in the plots.

Open with DEXTER

thumbnail Fig. A.4

Observed and modeled column densities in cm-2 at the UCHii stage. The observed values are shown in blue, the modeled values in black. The error bars are indicated by the vertical marks. Molecules are labeled in the plots.

Open with DEXTER


© ESO, 2015

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