The hyperfine Λ-doubling spectrum of 14N16O and 15N16O

Meerts, W. Leo; Dymanus, A.

doi:10.1016/0022-2852(72)90109-9

Cited by 106 publications

(45 citation statements)

References 15 publications

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“…Here we use the effective Hamiltonian H eff from [63] in the subspace of the levels ± 1/2 and ± 3/2 , where upper sign corresponds to the parity p in Eq. (12).…”

Section: Intermediate Couplingmentioning

confidence: 99%

Microwave and submillimeter molecular transitions and their dependence on fundamental constants

Kozlov

Levshakov

2013

Annalen der Physik

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Microwave and submillimeter molecular transition frequencies between nearly degenerated rotational levels, tunneling transitions, and mixed tunneling-rotational transitions show an extremely high sensitivity to the values of the finestructure constant, α, and the electron-to-proton mass ratio, μ. This review summarizes the theoretical background on quantum-mechanical calculations of the sensitivity coefficients of such transitions to tiny changes in α and μ for a number of molecules which are usually observed in Galactic and extragalactic sources, and discusses the possibility of testing the space-and time-invariance of fundamental constants through comparison between precise laboratory measurements of the molecular rest frequencies and their astronomical counterparts. In particular, diatomic radicals CH, OH, NH + , and a linear polyatomic radical C 3 H in electronic ground state, polyatomic molecules NH 3 , ND 3 , NH 2 D, NHD 2 , H 2 O 2 , H 3 O + , CH 3 OH, and CH 3 NH 2 in their tunneling and tunneling-rotational modes are considered. It is shown that sensitivity coefficients strongly depend on the quantum numbers of the corresponding transitions. This can be used for astrophysical tests of Einstein's Equivalence Principle all over the Universe at an unprecedented level of sensitivity of ∼10 −9 , which is a limit three to two orders of magnitude lower as compared to the current constraints on cosmological variations of α and μ: α/α < 10 −6 , μ/μ < 10 −7 .

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“…Here we use the effective Hamiltonian H eff from [63] in the subspace of the levels ± 1/2 and ± 3/2 , where upper sign corresponds to the parity p in Eq. (12).…”

Section: Intermediate Couplingmentioning

confidence: 99%

Microwave and submillimeter molecular transitions and their dependence on fundamental constants

Kozlov

Levshakov

2013

Annalen der Physik

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“…Good agreement with experiment up to the hyperfine level is achievable, even for a reduced set of only 11 parameters (Brown & Carrington 2003, p. 535). This should be contrasted with the pioneering study of NO by Meerts & Dymanus (1972), which required 24 parameters.…”

Section: Spectroscopy Of Nomentioning

confidence: 99%

The importance of non-LTE models for the interpretation of observations of interstellar NO

Lique

Tak²,

Kłos

et al. 2008

A&A

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Context. The ALMA and Herschel missions promise to deliver data of high spatial and spectral resolution at far-infrared and submillimeter wavelengths. Modeling these data will require the knowledge of accurate radiative and collisional rates for species of astrophysical interest. Aims. We calculate the rotational excitation rate coefficients of NO in collisions with He and check the validity of the LTE approach in interpreting observations of rotational lines of NO. Methods. State-to-state rate coefficients between the 360 lowest hyperfine levels of NO were calculated using the M J randomizing limit method for temperatures from 10 K to 350 K. We performed calculations of the excitation of NO using the new rate coefficients using a large velocity gradient (LVG) radiative transfer code. Results. The critical densities of the lines are found to be at > ∼ 10 5 cm −3 . The low dipole moment of NO ensures that the line emission is optically thin up to column densities of ∼10 15 cm −2 . Lines in the ground (Ω = 1/2) state are readily detectable in typical conditions (N(NO) = 10 13 cm −2 ; T = 10-30 K), whereas lines in the excited Ω = 3/2 state are observed only in warm (T > 50 K) regions with higher column densities (N(NO) = 10 14 cm −2 ). Line ratios of NO may well be used to constrain the ambient temperature and/or density. Conclusions. The new rate coefficients will help significantly in interpreting NO emission lines observed with current and future telescopes, and enable this molecule to become a powerful astrophysical tool.

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“…The 14 N 16 O line position and intensity data consist of millimeter and lower submillimeter data from Pickett et al [264] and tunable far-IR data from Varberg et al [265] in v = 0. The -doubling transitions in v = 0 were mainly taken from Meerts and Dymanus [266] ; additional data were taken from Refs. [267,268] .…”

Section: No (Molecule 8)mentioning

confidence: 99%

“…The -doubling transitions were taken from Meerts and Dymanus [266] . Millimeter and lower submillimeter data of the isotopologue 14 N 18 O were also published by Saleck et al [273] , and tunable far-IR data by Müller et al [263] .…”

Section: No (Molecule 8)mentioning

confidence: 99%