Assignment of the lambda 1369.13 diffuse interstellar absorption band and three other far-ultraviolet interstellar absorption lines to the CH molecule

Authors
Citation
Jkg. Watson, Assignment of the lambda 1369.13 diffuse interstellar absorption band and three other far-ultraviolet interstellar absorption lines to the CH molecule, ASTROPHYS J, 555(1), 2001, pp. 472-476
Citations number
43
Categorie Soggetti
Space Sciences
Journal title
ASTROPHYSICAL JOURNAL
ISSN journal
0004637X → ACNP
Volume
555
Issue
1
Year of publication
2001
Part
1
Pages
472 - 476
Database
ISI
SICI code
0004-637X(20010703)555:1<472:AOTL1D>2.0.ZU;2-S
Abstract
The three unidentified interstellar lines lambda lambda 1368.74, 1369.13, a nd 1370.87 are here assigned to the CH molecule, including the diffuse inte rstellar band (DIB) at 1369.13 Angstrom. A consistent rotational assignment of the interstellar lines and the 3d-X (2)Pi laboratory spectrum is presen ted. The predominant broadening mechanism of the lines appears to be predis sociation, which is found to be greater for lines with upper levels of d pa rity, including the DIB, than for lines with upper levels of c parity. The oscillator strength of the 3d-X (2)Pi transition is estimated to be f appro ximate to 0.033. Using the theoretical n* dependence of the parameters toge ther with the wavenumber of the observed laboratory Q-form branch, an unide ntified interstellar line at 1270.96 is assigned to the strongest line of t he 4d-X (2)Pi transition of CH.