Abstract
view Abstract Citations (48) References (27) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Excitation Rate Coefficients and Line Ratios for the Optical and Ultraviolet Transitions in S II Cai, Wei ; Pradhan, Anil K. Abstract New calculations are reported for electron excitation collision strengths, rate coefficients, transition probabilities, and line ratios for the astrophysically important optical and UV lines in S II. The collision strengths are calculated in the close coupling approximation using the R-matrix method. The present calculations are more extensive than previous ones, including all transitions among the 12 lowest LS terms and the corresponding 28 fine-structure levels in the collisional-radiative model for S II. While the present rate coefficients for electron impact excitation are within 10-30 percent of the previous values for the low-lying optical transitions employed as density diagnostics of H II regions and nebulae, the excitation rates for the UV transitions 4S super 03/2 - 4Psub 1/2,3/2,5/2 differ significantly from earlier calculations, by up to factor of 2. We describe temperature and density sensitive flux ratios for a number of UV lines. The present UV results are likely to be of interest in a more accurate interpretation of S II emission from the Io plasma torus in the magnetosphere of Jupiter, as well as other UV sources observed from the IUE, ASTRO 1, and the HST. Publication: The Astrophysical Journal Supplement Series Pub Date: September 1993 DOI: 10.1086/191824 Bibcode: 1993ApJS...88..329C Keywords: Electron Scattering; H Ii Regions; Optical Transition; Sulfur; Transition Probabilities; Ultraviolet Spectra; Active Galactic Nuclei; Collision Parameters; Coulomb Collisions; Eigenvalues; Electron Transitions; Io; Jupiter (Planet); Nebulae; Optical Thickness; Planetary Magnetospheres; Tables (Data); Toruses; Astrophysics; ATOMIC DATA; ISM: H II REGIONS; GALAXIES: ACTIVE; ISM: GENERAL; ULTRAVIOLET: GENERAL full text sources ADS |
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
