Einstein A coefficients and Oscillator Strengths for the
- Slides: 22
Einstein A coefficients and Oscillator Strengths for the A 2 П-X 2Σ+ (red) and B 2Σ+-X 2Σ+ (violet) Systems of CN R. S. RAM, J. S. A. BROOKE Department of Chemistry, University of York, Heslington, York YO 10 5 DD, UK. G. LI Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA D. W. SCHWENKE NASA Ames Research Center, Moffett Field, CA 94035 -10000, USA and P. F. BERNATH 2 Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529 USA
OUTLINE
Introduction
Interstellar CN Violet 0 -0 Diffuse interstellar cloud absorption towards the star HD 169454 Gredel et al. AA, 251, 625 (1991) [12 CN]/[13 CN]=38 See also, A. Mc. Kellar, PASP, 52, 187 (1940) Trot = 3 K (same temperature as the cosmic background radiation)
CN (3, 0) (red) in translucent clouds Early-type stars Schmidt et al. MNRAS 431, 1795 (2013) WGB stars Adamczak & Lambert Ap. J 765, 155 (2013)
Summary of Spectroscopic Studies A 2 П-X 2Σ+ (red system) 12 C 14 N: Ram et al. , JMS 263, 82 (2010) 13 C 14 N: Ram et al. , Ap. J Suppl. Ser. 188, 500 (2010); JMS 274, 22 (2012) More than 60 bands with v´=0 -22, v˝=0 -12, were analyzed for both isotopologues [4000 -22000 cm-1] B 2Σ+ -X 2Σ+ (violet system) 12 C 14 N: Ram et al. , JMS 237, 22 (2006) 13 C 14 N: Ram et al. , Ap. J Suppl. Ser. 194, 34 (2011) More than 50 bands with v´=0 -15, v˝=0 -15 were analyzed [20000 -29000 cm-1] 12 C 15 N: Colin & Bernath, JMS 273, 30 (2012)
Lifetimes of the A 2Π state Lu, Huang, Halpern, Ap. J 395, 710 (1992)
Method of Calculation
Comparison of the A 2Π state lifetimes (in μs)
Comparison of the B 2Σ+ state lifetimes (in ns)
Calculation of Av'v" and fv'v" values of the A 2 П-X 2Σ+ transition of CP A 2 П-X 2Σ+ Measurements B-X Herzberg (1930) B-A Bärwald et al. (1934) IRC+10216 Guélin et al. (1990) Cernicharo et al. (2000) Tenenbaum et al. (2007) Ram & Bernath, JMS 122, 282 (1987) Ram & Bernath, JMS 152, 89 (1992) Microwave and THz measurements Saito et al. Ap. J 341, 1114 (1989) Klein et al. Z. Naturforsch 54 a, 187 (1999) Transition dipole moments Brouckère & Feller, J. Phys. B 31, 5053 (1998) Intensity calculations for 75, A-X bands with v=0 -8 levels of both states
CONCLUSION
ACKNOWLEDGMENTS LEVERHULME TRUST NASA LABORATORY ASTROPHYSICS PROGRAM NATIONAL SOLAR OBSERVATORY End Thank you for your attention !
Star Classification Astronomers classify stars by color using a series of letters: O, B, A, F, G, K and M. Under this classification, O stars are the hottest, and M stars are the coolest, with the other letters coming in between. O stars are “blue”, A stars are “white”, G stars are “yellow”, and M stars are red.
- Chemistry formula
- Chemical formula with subscript
- What is a combustion reaction example
- What are subscripts in chemistry
- Coefficients vs subscripts
- 1 variable equations worksheet
- Solve equations with rational coefficients
- Fourier series integral
- Equating coefficients
- Solving equations with fractional coefficients
- Unstandardized coefficients
- Collect like terms
- Addition of three angular momenta
- Canonical discriminant analysis
- L^2 operator
- Gregory coefficients
- Solving linear equations with rational coefficients
- How to add square roots with coefficients
- How to multiply radicals with coefficients
- Fresnel coefficients
- Series de fourier
- Series representation
- Annihilator method examples