Millimeter-Wave Spectroscopy of Three Highly Reactive Astrophysical Molecules: Silicon Carbide, Silicon Monoxide, and CARBON(3) HYDROGEN(2)

Details Millimeter-Wave Spectroscopy of Three Highly Reactive Astrophysical Molecules: Silicon Carbide, Silicon Monoxide, and CARBON(3) HYDROGEN(2) Millimeter-Wave Spectroscopy of Three Highly Reactive Astrophysical Molecules: Silicon Carbide, Silicon Monoxide, and CARBON(3) HYDROGEN(2)

Jan 1993

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993phdt........56m&link_type=abstract

Thesis (PH.D.)--HARVARD UNIVERSITY, 1993.Source: Dissertation Abstracts International, Volume: 54-06, Section: B, page: 3143.

Astronomy and Astrophysics

Astronomy

Scientific paper

Rotational transitions or three highly reactive molecules of considerable astrophysical interest (SiC, SiO, and c-C_3H_2) were measured, and a number of spectroscopic parameters of these molecules determined. The well-resolved hyperfine structure of two isotopes of SiC with nuclear spins (Si 13C, and ^ {29}SiC) studied at millimeter wavelengths allowed determination of the hyperfine constants to accuracies of better than 1%. Accurate values or these constants provide stringent tests for ab initio calculations of the wave function of SiC. Millimeter-wave spectra of a number of vibrationally excited states of c-C_3H _2 were observed. Although in absence of infrared data or theoretical calculations of the vibration -rotation constants, assignment of vibrational states based solely on pure rotational spectrum is not straightforward, considerable progress in assignment of the vibrational states detected was made. Detection of the millimeter -wave rotational spectrum of highly vibrationally excited SiO (up to v = 40) demonstrated the radically non-equilibrium distribution of vibrational state populations that can occur in glow discharges, and provided the necessary data for calculation of the intermolecular potential function by the RKR procedure. Accurate values of molecular constants of these molecules allowed prediction of their rotational transitions into the far-infrared to accuracies required for radioastronomy. Furthermore, the values of molecular constants in vibrationally excited c-C_3H_2 can be very useful for future infrared spectroscopy on them. Considerable progress was also made towards construction and testing of a millimeter-wave multi-pass spectrometer (White cell). A path length of ~60 m with a physical separation of 2m at a frequency of ~300 GHz was obtained, potentially resulting in a factor of ten improvement in the sensitivity or the spectrometer compared with the instrument used to obtain the data presented in this thesis.

Affiliated with

Also associated with

No associations

Rating

Millimeter-Wave Spectroscopy of Three Highly Reactive Astrophysical Molecules: Silicon Carbide, Silicon Monoxide, and CARBON(3) HYDROGEN(2) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Millimeter-Wave Spectroscopy of Three Highly Reactive Astrophysical Molecules: Silicon Carbide, Silicon Monoxide, and CARBON(3) HYDROGEN(2), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Millimeter-Wave Spectroscopy of Three Highly Reactive Astrophysical Molecules: Silicon Carbide, Silicon Monoxide, and CARBON(3) HYDROGEN(2) will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1264557