dc.creator Yu, Shanshan en_US dc.creator Pearson, John C. en_US dc.creator Drouin, Brian J. en_US dc.creator Walters, Adam en_US dc.creator Müller, Holger S. P. en_US dc.creator Brunken, Sandra en_US dc.date.accessioned 2010-07-12T14:30:56Z dc.date.available 2010-07-12T14:30:56Z dc.date.issued 2010 en_US dc.identifier 2010-TJ-10 en_US dc.identifier.uri http://hdl.handle.net/1811/46418 dc.description Author Institution: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109; Centre d'Etude Spatiale des Rayonnements, Universite de Toulouse [UPS], CNRS [UMR 5187], 9 avenue du Colonel Roche, BP 44346, F-31028 Toulouse Cedex 4, France; I. Physikalisches Institut, Universitat zu Koln, 50937 Koln, Germany en_US dc.description.abstract The observation and characterization of water spectra have been intensely pursued in the astrophysical community. Its rotational transitions in the ground, (010) ($v_2 = 1$), (020), (100), and (001) states are primary targets of the ongoing Herschel mission. In this study, laboratory terahertz spectroscopy of water was carried out at JPL and Cologne, with the goals to measure all transitions HIFI might see and critically review and fit the lowest 5 vibrational states. DC discharge, radio frequency discharge and heating tapes were used to generate highly excited water. A total of 145 pure rotational transitions in the (000), (010), (020), (100), and (001) states of water were observed in the 293$-$1969~GHz region. Of these, 86 have been detected for the first time with MW accuracy. So far, the $1(1,0)-1(0,1)$ transition was observed for all five states; the $2(1,2)-1(0,1)$ transition was observed for (000), (100), and (001) but is missing for (010) (1753914~GHz) and (020) (1872972~GHz); the $1(1,1)-0(0,0)$ transition was observed for all states but (020) (1332967~GHz). The analysis is still in progress, and we will present the most recent fitting results to date. There are difficulties in fitting water spectra, such as the strong centrifugal distortion, which gives a non-convergent Watson Hamiltonian. In addition, the first triad states (100, 020, and 001) are strongly coupled. The latest attempt at a global fit of these 5 states using Euler series achieved a reduced RMS of 8.4 (Pickett et al. 2005, J. Mol. Spectrosc. 233, 174). en_US dc.language.iso en en_US dc.publisher Ohio State University en_US dc.title TERAHERTZ SPECTROSCOPY OF EXCITED WATER en_US dc.type Article en_US dc.type Image en_US dc.type Presentation en_US
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