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Table 1

Molecular cloud parameters from Herschel data.

Cloud D M Σ N(H2) ⟩ ΔAv A v,pk Av (DP) σ η s α
[kpc] [104M] [M pc-2] [1021 cm-2] [mag] [mag] [mag]
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)

High-mass SF regions
NGC 3603 7.0 50.4 (97.1) 60 (116) 3.24 (6.24) 3.0 ± 0.5 1.6 (4.8) 4.9 (8.1) 0.52 (0.27) –1.31 (–1.61) 2.53 (2.24)
Carina 2.3 34.5 (59.5) 50 (89) 2.79 (4.79) 2.0 ± 0.2 2.6 (4.4) 5.5 (7.4) 0.38 (0.20) –2.66 (–3.04) 1.75 (1.66)
Low-mass SF regions
Maddalena 2.2 35.2 (68.2) 37 (76) 2.13 (4.13) 2.0 ± 0.25 1.9 (3.9) 4.9 (7.8) 0.32 (0.20) –3.69 (–5.21) 1.54 (1.38)
Auriga 0.45 2.2 (3.7) 28 (47) 1.51 (2.52) 0.8 ± 0.1 1.4 (2.3) 3.5 (4.0) 0.45 (0.25) –2.54 (–3.05) 1.79 (1.66)

Corrected 44  ±  7 2.42  ±  0.38 1.88  ±  0.26 4.70  ±  0.42 0.42  ±  0.04 –2.55  ±  0.49 1.90  ±  0.22
Original 82 ± 14 4.42 ± 0.77 3.85 ± 0.55 6.83 ± 0.95 0.23 ± 0.02 –3.22 ± 0.74 1.74 ± 0.18

Notes. All values in parenthesis are the ones determined from the original maps before correction for LOS contamination. The last two lines give the average values (and standard deviation) from the corrected and uncorrected maps. (1) Distance D of the cloud. (2) Mass MN(H2)D2. The H2 column density determination assumes a mean atomic weight per molecule of 2.3. The total mass was determined above an Av level of ~1 mag, which is a typical value for estimating molecular cloud extent (e.g., Lada et al. 2010). For the uncorrected maps, we determine the mass within the same area (above a threshold of Av = 1 + ΔAv [mag]). We note that for Auriga, the mass estimated by Harvey et al. (2013) is slightly higher (4.9 × 104M) than our value. Both mass values were derived from an area of ~13 deg2, while the mass of Auriga given in Lada et al. (2010) of 1.1 × 105M is determined from the whole cloud complex, covering 80 deg2. (3) Surface density (Σ = M/area). (4) Average column density (above a level of 1021 cm-2). (5) Background/foreground level of visual extinction. The error is the root mean square from the pixel statistics used to determine the contamination. (6) Peak of PDF in visual extinction. (7) Visual extinction value of the deviation point where the PDF starts to deviate from the lognormal shape at high column densities. (8) Dispersion of the fitted lognormal PDF. (9) Slope s of the high-density tail of the PDF, determined by linear regression (the χ2 value is given in the panels of the PDF). We excluded the noisier and less well sampled points at the high column density end of the PDF. (10) Exponent of the spherical density distribution ρrα, determined from s with α = −2 /s + 1 (Federrath & Klessen 2013).

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