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Appendix A: Detected lines per species for all sources

The line assignment and detection is based on Gaussian fitting with the following criteria: (i) the fitted line position has to be within ±1 MHz of the catalog frequency; (ii) the FWHM is consistent with the those given in Table 1; and (iii) the peak intensity has at least a S/N = 3. The errors on the integrated intensities are computed as follows.

The integrated main beam temperatures, , were obtained by Gaussian fits to the lines (Eq. (A.1)). (A.1)with

where T₀ is the peak intensity and ΔV is the FWHM of the line. The error, , is calculated from Eq. (A.2). (A.2)with

and

where rms is the root mean square amplitude of the noise in the spectral bin δv, cal is the calibration uncertainty of the telescope, and σ’s are the statistical errors on T₀ and ΔV from the Gaussian fits.

The errors on the integrated intensities derived from Eq. (A.2) include all statistical errors from the Gaussian fit. (A.3)For undetected transitions the upper limits were determined as 3σ limits (Eq. (A.4)) using: (A.4)where 1.2 is the coefficient related to the calibration uncertainty of 20%.

CLASS was used to determine the Gaussian fits and the uncertainties in the individual parameters. The formal errors on the integrated intensities derived from Eq. (A.3) in some cases yield a S/N < 2.5. This is caused by: (i) a conservative estimate of the statistical error on the FWHM parameter in the Gaussian fitter of CLASS; (ii) all statistical errors are included into our error calculation. Considering the higher S/N on the peak intensity, a more traditional error estimate without the statistical errors from the Gaussian fit (Eq. (A.3)) would result in a S/N > 3 for the integrated intensity as well. All weak line fits were confirmed by visual inspection.

Appendix B: Rotation diagrams

RTD diagrams for H₂CO, CH₃OH, C₂H₅OH, HNCO, NH₂CHO, CH₃CN, C₂H₅CN, HCOOCH₃, CH₃OCH₃, CH₂CO and CH₃CCH. Lines from different frequency bands are corrected for differential beam dilution assuming a R_{T = 100  K} source size for the warm species and 14″ source size for the cold species, as indicated in the plots. Optically thin, unblended lines with S/N ≳ 2 are marked with filled circles. Lines with high S/N (≲2) are marked with diamonds, those included in the fit with filled diamonds. Optically thick lines and blended lines are marked with open squares and triangles, respectively. Upper limits are marked with arrows. Upper limits used to constrain the fit are marked with filled stars. The error bars are calculated using Eq. (A.2).

Appendix C: Weeds model parameters

Appendix D: Additional detections

Several lines of other species were found in the observed frequency ranges, particularly in the line-rich G31.41+0.31. Table D.1 lists additional detections with column densities obtained from the Weeds analysis with the best T_ex when this could be derived. Several transitions of acetone, CH₃COCH₃, are detected. In G31, the best agreement is obtained at 100 K, whereas for IRAS 18089, this is T_ex = 300 K. No CH₃COCH₃ was detected in IRAS 20126, and the tabulated value is an upper limit at 300 K. Figure D.1 shows the strongest acetone lines in G31 together with the Weeds model.

Glycoaldehyde, HCOCH₂OH, has previously been detected in G31 (Beltrán et al. 2009), has several lines in the covered ranges. All lines are however blended with other transitions, and only upper limit could therefore be derived reliably. The tabulated column density is for a temperature of 300 K, constrained by non-detection of lines with low E_up.

Two transitions of HC₃N are detected at 218.325 GHz (E_up131.0 K) (J = 24 → 23) and 354.697 GHz (E_up340.5 K) (J = 39 → 38). The Weeds model on the two lines, well separated in E_up, gives a beam averaged column density of 7 × 10¹³ cm^-2 and a temperature of 150 K for G31. The HC₃N emission cannot be matched with emission contained within a 2.0″ volume as the low-E_uptransition becomes optically thick. For IRAS 20126, the tabulated column density is at 100 K, constrained by the two transitions. Only the high E_up transition was covered for IRAS 18089 giving a column density of 3 × 10¹³ cm^-2 at 150 K and 6 × 10¹³ cm^-2 at 100 K.

Several CH₃NH₂ transitions are observed with a T_ex of 150 K. Blends with other species make the rotation temperature and column density inaccurate, however. Several unidentified lines coincide with NH₂CH₂CH₂OH, but only upper limits of 1.0× 10¹⁶ cm^-2 at 100-300 K could be derived reliably using Weeds.

Several weak lines of NH₂CN are detected, with a T_ex of 50 K derived from the Weeds model, but line blends make the rotation temperature and column density inaccurate. For CN, SO, ³⁴SO, O¹³CS, OC³⁴S, SO₂, ³³SO₂, C³⁴S, and CP not enough lines were observed to derive T_ex values, and tabulated column densities are assuming a temperature of 50 K.

One line of HCN, J = 4–3, was observed. HCN emission in G31 is composed of a broad (12 km s^-1) and a narrow (6 km s^-1) component (redshifted by 2.5 km s^-1) causing self-absorption. For IRAS 18089, the broad component has a width of 7 km s^-1 and narrow 4 km s^-1 (redshifted by 1 km s^-1). For IRAS 20126 the HCN emission has a very broad 20 km s^-1 component blueshifted by 2 km s^-1 and a narrow (5 km s^-1) component redshifted by 1 km s^-1. The tabulated column densities are those derived from the H¹³CN column density.

© ESO, 2013