Access to Astronomical Catalogues

← Click to display the menu
J/A+A/531/A103      Collisional excitation of sulfur dioxide (Cernicharo+, 2011)

Collisional excitation of sulfur dioxide, SO2, in cold molecular clouds. Cernicharo J., Spielfiedel A., Balanca C., Dayou F., Senent M.-L., Feautrier N., Faure A., Cressiot-Vincent L., Wiesenfeld L., Pardo J.R. <Astron. Astrophys. 531, A103 (2011)> =2011A&A...531A.103C
ADC_Keywords: Atomic physics ; Molecular clouds Keywords: molecular processes - ISM : molecules - ISM : abundances Abstract: We present collisional rate coefficients for SO2 with ortho and para molecular hydrogen for the physical conditions prevailing in dark molecular clouds. Rate coefficients for the first 31 rotational levels of this species (energies up to 55K) and for temperatures between 5 and 30K are provided. We have found that these rate coefficients are about ten times more than those previously computed for SO2 with helium. We calculated the expected emission of the centimeter wavelength lines of SO2. We find that the transition connecting the metastable 202 level with the 111 one is in absorption against the cosmic background for a wide range of densities. The 404-313 line is found to be inverted for densities below a few 104cm-3. We observed the 111-202 transition with the 100m Green Bank Telescope towards some dark clouds. The line is observed, as expected, in absorption and provides an abundance of SO2 in these objects of a few 10-10. The potential use of millimeter lines of SO2 as tracers of the physical conditions of dark clouds is discussed. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 27 31 SO2 calculated energy levels table5.dat 71 961 Rate coefficients of SO2 in collision with para-H2(j2=0,2) as function of kinetic temperature table6.dat 71 961 Rate coefficients of SO2 in collision with ortho-H2(j2=1) as function of kinetic temperature
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Level Level number 4- 11 A8 --- Trans j(Ka,Kc) value 13- 19 F7.4 cm-1 E This work energy level 21- 27 F7.4 cm-1 EJPL JPL energy level (1)
Note (1): Pickett et al., 1998,J. Quant. Spectrosc. Rad. Transfer 60, 883 see also JPL Molecular Spectroscopy Catalog: http://spec.jpl.nasa.gov
Byte-by-byte Description of file: table5.dat table6.dat
Bytes Format Units Label Explanations
1- 2 I2 --- I Initial level 4- 5 I2 --- F Final level 7- 16 E10.5 cm3/s Rate(5) Rate coefficient at temperature Tkin=5K 18- 27 E10.5 cm3/s Rate(10) Rate coefficient at temperature Tkin=10K 29- 38 E10.5 cm3/s Rate(15) Rate coefficient at temperature Tkin=15K 40- 49 E10.5 cm3/s Rate(20) Rate coefficient at temperature Tkin=20K 51- 60 E10.5 cm3/s Rate(25) Rate coefficient at temperature Tkin=25K 62- 71 E10.5 cm3/s Rate(30) Rate coefficient at temperature Tkin=30K
Acknowledgements: Nicole Feautrier, Nicole.Feautrier(at)obspm.fr
(End) Patricia Vannier [CDS] 04-May-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service

© UDS/CNRS

Contact