Fourier Transform Emission Spectroscopy of the B 2 Σ + -X 2 Σ + (Violet) System of CN R.S. Ram Department of Chemistry, University of Arizona, Tucson, AZ 85721 S. P. Davis, L. Wallace National Optical Astronomy Observatory, Tucson, AZ 85726 R. Engleman Department of Chemistry, University of New Mexico, Albuquerque, NM 87131 D. R. T. Appadoo Canadian Light Source, 101 Perimeter Road, Saskatoon, Sask. Canada S7N OX4 P. F. Bernath Department of Chemistry, University of Waterloo, Waterloo, Ont., Canada N2L 3G1
15
Embed
Fourier Transform Emission Spectroscopy of the B 2 Σ + -X 2 Σ + (Violet) System of CN R.S. Ram Department of Chemistry, University of Arizona, Tucson,
Interstellar CN Violet 0-0 Diffuse interstellar cloud absorption towards the star HD Gredel et al. AA, 251, 625 (1991) See also, A. McKellar, PASP, 52, 187 (1940) (Bob McKellar’s father!) T rot = 3 K (same temperature as the cosmic background radiation) [CN]/[ 13 CN]=38
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Fourier Transform Emission Spectroscopy of the B2Σ+-X2Σ+ (Violet) System of CN
R.S. RamDepartment of Chemistry, University of Arizona, Tucson, AZ
85721S. P. Davis, L. Wallace
National Optical Astronomy Observatory, Tucson, AZ 85726R. Engleman
Department of Chemistry, University of New Mexico, Albuquerque, NM 87131
D. R. T. AppadooCanadian Light Source, 101 Perimeter Road, Saskatoon,
Sask. Canada S7N OX4P. F. Bernath
Department of Chemistry, University of Waterloo, Waterloo, Ont., Canada N2L 3G1
Introduction“The CN radical has been the subject of
extensive studies because of its importance in chemical kinetics, flame diagnostics, and astrophysics. The CN radical is found in many extraterrestrial sources including the Sun, stellar atmospheres, comets, dark interstellar clouds, and diffuse interstellar clouds.” from Ram et al. JMS, 237, 247 (2006).
Interstellar CN Violet 0-0Diffuse interstellar cloud absorption towards the star HD169454Gredel et al. AA, 251, 625 (1991)See also, A. McKellar, PASP, 52, 187 (1940)(Bob McKellar’s father!)
Trot = 3 K (same temperature as the cosmic background radiation)
[CN]/[13CN]=38
Circumstellar CN Violet 0-0
Circumstellar cloud absorption towards the star HD56126Bakker & Lambert, ApJ 502, 417 (1998)
Trot = 12 K
[CN]/[13CN]=38
Lines are saturated.
Solar CN Violet (Fraunhofer Lines)
Absorption in photosphere of the SunL. Wallace,Kitt Peak Solar Atlas
Trot = 6000 K in the solar photosphere[CN]/[13CN]=90
Same as on Earth
Comet Linear CN Violet Emission
Notice the “Swings effect”Arpigny et al. Science 301, 1522 (2003)
[CN]/[13CN]=115,[CN]/[C15N]=140(269 on Earth)
Red Rectangle CN Violet
Emission and absorption!Hobbs et al. ApJ 615, 947 (2004)
McMath-Pierce Solar Observatory
McMath-Pierce FTS
CN Violet Δv=+2 Sequence
CN was made by S. Davis using a microwave discharge of nitrogen with a trace of methane. The discharge tube was cooled by a flow of N2 vapor from liquid nitrogen boil-off.
CN Violet 10-10 Band
CN Data UsedStarting point was previous analysis of
Prasad & Bernath 1991 (jet-cooled emission data, plus IR and microwave)
• New microwave: Klisch et al. v=0-7• New IR: Horka et al. 1-0 to 8-7 bands• Electronic: Our new B-X data for v’ &
v” up to 14 and 15-15 band plus Douglas & Routly, Ito et al. for v’s > 15