Some New Measurements of the Ground and v₂ = 1 States of HDO in the Region 200 – 750 GHz

Citation

Kelly, Melissa Ann (2003) Some New Measurements of the Ground and v₂ = 1 States of HDO in the Region 200 – 750 GHz. Master's thesis, California Institute of Technology. doi:10.7907/P33F-HD20. https://resolver.caltech.edu/CaltechETD:etd-09162002-140330

Abstract

To facilitate measurements of HDO in molecular clouds, late-type stars and planetary atmospheres, several new lines of HDO were measured between 200 and 750 GHz. The measurements were done in a one-meter gas flow cell, with specially constructed diode multiplier sources and a liquid helium cooled InSb hot-electron bolometer. The lines measured were of very low intensity, thanks to their higher J and K values. Both a-type and b-type transitions were observed, in the vibrational ground state (000) and the first excited bending state (010). These lines were added to existing HDO spectral lines and fit using a least-squares regression of an Euler series Hamiltonian that has proven useful in the analysis of molecules with large vibrational amplitudes. The results were comparable in precision to existing analyses. The data will be beneficial to two upcoming remote sensing missions designed to investigate the far IR and microwave regions: SOFIA, an airborne observatory that will carry a 2.5m telescope and detectors into the upper atmosphere, and the Herschel space observatory, a cryogenically cooled 3.5m telescope that will operate at the L2 Lagrangian point some 1.5 million km from the Earth.

Thesis Files