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Table 3

Results of the excitation analysis toward the off-center regions of W49A.

I. Rotation diagrams
Northern clump Eastern tail Southwest clump
Trot[K] 67 ± 13 56 ± 3 62 ± 11
Ntota [1013 cm-2] 2.26 ± 0.48 1.82 ± 0.46 1.68 ± 0.36
Source size [′′] 14.44 14.44 14.44
Tex[K] 67 55 61
Ntot,1b [1013 cm-2] 2.2 1.9 1.7
II. Non-LTE calculation
Northern clump Eastern tail Southwest clump
Tkin[K]c 98 68 85
N[H2CO] [cm-2] 0.7−1.1 ×  1014 4.9−5.0 ×  1013 3.2−4.5  ×  1014
N[HCN] [cm-2] 1.5−2 × 1014 7−8 × 1013 6.2−9.6 ×  1014
n[cm-3]d 5.6 ×  105 1.2 ×  106 1.3 ×  105

Notes. 

(a)

Total beam-averaged column density calculated using the assumption that the lines are optically thin, the level populations can be characterized by a single excitation temperature and the emission fills the telescope beam.

(b)

Total source-averaged column density given by the χ2 minimization, including a correction for the optical depth and a beam dilution factor. The errors show the 1-σ upper and lower limits of the best fit.

(c)

The uncertainty of the kinetic temperatures is ~ 30%.

(d)

The uncertainty of the density estimates is a factor of 2.

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