Diode-Laser Measurements of H2-Broadening Coefficients in the ν2Band of HCN

Landrain, Véronique; Blanquet, Ghislain; Lepère, Muriel; Walrand, Jacques; Bouanich, Jean-Pierre

doi:10.1006/jmsp.1996.7223

Cited by 8 publications

(3 citation statements)

References 13 publications

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“…3, along with optimised CO and HCN profiles, retrieved from the high S/N observations of CO and HCN (not shown). As the CS pressure broadening coefficient (γ) was not found in the literature, we nominally used the value of the HCN(4-3) line, γ = 0.121 cm −1 /atm with a temperature exponent n = 0.74 (Landrain et al 1997;Rohart et al 2007). …”

Section: Modelling and Resultsmentioning

confidence: 99%

Detection of CS in Neptune’s atmosphere from ALMA observations

Moreno

Lellouch

Cavalié

et al. 2017

A&A

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Context. The large and vertically non-uniform abundance of CO in Neptune's atmosphere has been interpreted as the result of past cometary impact(s), either single or distributed in size and time, which could also be at the origin of Neptune's HCN. Aims. We aim to provide observational support for this scenario by searching for other comet-induced species, in particular carbon sulfide (CS) which has been observed continuously in Jupiter since the 1994 Shoemaker-Levy 9 impacts. Methods. In April 2016 we used the ALMA interferometer to search for CS(7-6) at 342.883 GHz in Neptune. Results. We report on the detection of CS in Neptune's atmosphere, the first unambiguous observation of a sulfur-bearing species in a giant planet beyond Jupiter. Carbon sulfide appears to be present only at submillibar levels, with a column density of (2.0-3.1) × 10 12 cm −2 , and a typical mixing ratio of (2−20) × 10 −11 that depends on its precise vertical location. The favoured origin of CS is deposition by a putative large comet impact several centuries ago, and the strong depletion of CS with respect to CO -compared to the Jupiter case -is likely due to the CS sticking to aerosols or clustering to form polymers in Neptune's lower stratosphere. Conclusions. The CS detection, along with recent analyses of the CO profile, reinforces the presumption of a large comet impact into Neptune ∼1000 yr ago, that delivered CO, CS, and HCN at the same time.

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Section: Modelling and Resultsmentioning

confidence: 99%

Detection of CS in Neptune’s atmosphere from ALMA observations

Moreno

Lellouch

Cavalié

et al. 2017

A&A

View full text Add to dashboard Cite

show abstract

“…Several other more recent experimental studies on self-and foreign gas-broadening and pressure-induced shifts of HCN m 2 transitions are available in the literature [26][27][28][29][30][31]. All of these recent studies analyzed spectra recorded with tunable diode laser spectrometers, to determine self-, N 2 -, H 2 -, and Ar-broadening coefficients as well as self-, H 2 -, and He-pressure-induced shift coefficients for select transitions in the P-, Q-, and R-branches of the m 2 band.…”

Section: Introductionmentioning

confidence: 99%

“…A number of studies involving both low and high-resolution measurements are available in the literature for the m 2 bending mode of HCN and its isotopologues [18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Earlier absolute intensity measurements and determinations of the dipole moment [18][19][20] were based on spectra obtained with low-resolution recording instruments and at high gas pressures to reduce errors arising from saturation effects.…”

Section: Introductionmentioning

confidence: 99%