Free Access

Table 7

Results of RATRAN models of fractional abundances of certain molecules in R CrA IRS7B and similar modelling results from the literature for other protostellar sources.

IRS7B I16293a Class 0b Class Ib Prestellarb
Molecule abundance abundance abundance abundance abundance

COc 1.4 × 10-4 ... 3.3 × 10-5 2.1 × 10-5 1.1 × 10-4 1.4 × 10-5
C17O 5.7 × 10-8 6.9 1.6 × 10-8 ... ... ...
C18O 3.2 × 10-7 ... 6.2 × 10-8 ... ... ...
HCO+c 3.8 × 10-9 ... 1.4 × 10-9 2.2 × 10-9 1.1 × 10-8 8.0 × 10-10
HC18O+ 6.8 × 10-12 3.6 6.4 × 10-12 ... ... ...
SO 1.9 × 10-9 33.6 4.4 × 10-9 2.0 × 10-9 2.3 × 10-9 1.5 × 10-9
CSc 6.7 × 10-9 ... 3.0 × 10-9 1.5 × 10-9 4.3 × 10-9 1.8 × 10-9
13CS 8.8 × 10-11 ... ... ... ... ...
C34S 2.1 × 10-10 16.2 1.2 × 10-10 ... ... ...
C33S 6.8 × 10-11 ... ... ... ... ...
CN outerd 4.5 × 10-9 8.5 8.0 × 10-11 6.9 × 10-10 3.0 × 10-9 4.8 × 10-9
CN innerd < 1 × 10-9
DCN 7.2 × 10-11 14.1 1.3 × 10-11 1.4 × 10-11 ... 7.7 × 10-12
DNC 6.8 × 10-11 ... 4.2 × 10-12 ... ... ...
HNCO 1.2 × 10-10 0.002 1.3 × 10-10 ... ... ...
HC3N 3.3 × 10-9 11.2 1.5 × 10-10 3.5 × 10-10 3.1 × 10-9 8.2 × 10-10
c-C3H2 3.0 × 10-10 12.9 1.6 × 10-11 ... ... ...

Notes. The reduced-χ2 values for IRS7B assume a 10% calibration error and can only be computed for species with at least two spectral lines.

(a)

IRAS 16293-2422, Schöier et al. (2002).

(b)

Average of sources in Jørgensen et al. (2004).

(c)

The abundances for these optically thick species have been calculated from the optically thin isotopologues assuming local ISM isotope ratios (Wilson 1999; Chin et al. 1996).

(d)

The CN fit was performed with a step in the abundance profile at 370 AU (where T ≈ 30 K).

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.