Accurate rotational constants of CO, HCl, and HF: Spectral standards for the 0.3- to 6-THz (10- to 200-cm−1) region

Nolt, I. G.; Radostitz, J. V.; Dilonardo, G.; Evenson, K. M.; Jennings, D. A.; Leopold, K. R.; Vanek, M.D.; Zink, L. R.; Hinz, A.; Chance, K.

doi:10.1016/0022-2852(87)90099-3

Cited by 151 publications

(66 citation statements)

References 12 publications

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“…We observed the J = 1−0 transition of HF, with rest frequency 1232.4763 GHz (Nolt et al 1987), in the upper sideband of the Band 5a HIFI receiver. To help determine whether any observed feature did indeed lie in the upper sideband, three observations were carried out with slightly different settings of the local oscillator (LO) frequency.…”

Section: Observations and Data Reductionmentioning

confidence: 89%

Strong absorption by interstellar hydrogen fluoride:Herschel/HIFI observations of the sight-line to G10.6–0.4 (W31C)

Neufeld¹,

Sonnentrucker²,

Phillips

et al. 2010

A&A

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We report the detection of strong absorption by interstellar hydrogen fluoride along the sight-line to the submillimeter continuum source G10.6-0.4 (W31C). We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 1232.4763 GHz J = 1−0 HF transition in the upper sideband of the Band 5a receiver. The resultant spectrum shows weak HF emission from G10.6-0.4 at LSR velocities in the range -10 to -3 km s −1 , accompanied by strong absorption by foreground material at LSR velocities in the range 15 to 50 km s −1 . The spectrum is similar to that of the 1113.3430 GHz 1 11 −0 00 transition of para-water, although at some frequencies the HF (hydrogen fluoride) optical depth clearly exceeds that of para-H 2 O. The optically-thick HF absorption that we have observed places a conservative lower limit of 1.6 × 10 14 cm −2 on the HF column density along the sight-line to G10.6-0.4. Our lower limit on the HF abundance, 6 × 10 −9 relative to hydrogen nuclei, implies that hydrogen fluoride accounts for between ∼30% and 100% of the fluorine nuclei in the gas phase along this sight-line. This observation corroborates theoretical predictions that -because the unique thermochemistry of fluorine permits the exothermic reaction of F atoms with molecular hydrogen -HF will be the dominant reservoir of interstellar fluorine under a wide range of conditions.

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Section: Observations and Data Reductionmentioning

confidence: 89%

Strong absorption by interstellar hydrogen fluoride:Herschel/HIFI observations of the sight-line to G10.6–0.4 (W31C)

Neufeld¹,

Sonnentrucker²,

Phillips

et al. 2010

A&A

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“…The much smaller splitting caused by the I = 1/2 spin of the H nucleus can be resolved in the laboratory (Kaiser 1970;Cazzoli & Puzzarini 2004), but not in astronomical observations. The HF J(1−0) line at 1232.4762 GHz (Nolt et al 1987) was observed in the upper side band of the band 5a receiver. Notes.…”

Section: Observationsmentioning

confidence: 94%

Searches for HCl and HF in comets 103P/Hartley 2 and C/2009 P1 (Garradd) with theHerschelSpace Observatory

Bockelée‐Morvan

Biver

Crovisier

et al. 2014

A&A

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Context. Hydrogen chloride (HCl) and hydrogen fluoride (HF) are expected to be the main reservoirs of fluorine and chlorine over a wide range of conditions, wherever hydrogen is predominantly molecular. They are found to be strongly depleted in dense molecular clouds, suggesting freeze-out onto grains in such cold environments. We can then expect that HCl and HF were also the major carriers of Cl and F in the gas and icy phases of the outer solar nebula, and were incorporated into comets. Aims. We aimed to measure the HCl and HF abundances in cometary ices as they can provide insights on the halogen chemistry in the early solar nebula. Methods. We searched for the J(1−0) lines of HCl and HF at 626 and 1232 GHz, respectively, using the Heterodyne Instrument for the Far-Infrared (HIFI) onboard the Herschel Space Observatory. HCl was searched for in comets 103P/Hartley 2 and C/2009 P1 (Garradd), whereas observations of HF were conducted in comet C/2009 P1 (Garradd). In addition, observations of H 2 O and H 2 18 O lines were performed in C/2009 P1 (Garradd) to measure the H 2 O production rate at the time of the HCl and HF observations. Three lines of CH 3 OH were serendipitously observed in the HCl receiver setting. Results. HCl is not detected, whereas a marginal (3.6-σ) detection of HF is obtained. The upper limits for the HCl abundance relative to water are 0.011% and 0.022%, for comet 103P/Hartley 2 and C/2009 P1 (Garradd), respectively, showing that HCl is depleted with respect to the solar Cl/O abundance by a factor more than 6 +6 −3 in 103P/Hartley 2, where the error is related to the uncertainty in the chlorine solar abundance. The marginal HF detection obtained in C/2009 P1 (Garradd) corresponds to an HF abundance relative to water of (1.8 ± 0.5) × 10 −4 , which is approximately consistent with a solar photospheric F/O abundance. The inferred water production rate in comet C/2009 P1 (Garradd) is (1.1±0.3)×10 29 s −1 and (0.75±0.05)×10 29 s −1 on 17 and 23 February 2012, respectively. CH 3 OH abundances relative to water are 2.7 ± 0.3% and 3.4 ± 0.6%, for comets 103P/Hartley 2 and C/2009 P1 (Garradd), respectively. Conclusions. The observed depletion of HCl suggests that HCl was not the main reservoir of chlorine in the regions of the solar nebula where these comets formed. HF was possibly the main fluorine compound in the gas phase of the outer solar nebula. However, this needs to be confirmed by future measurements.

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“…This is large enough to avoid any reference position contamination from the hot core and shock, but might encompass emission from the extended molecular ridge. Both HF and para-H 18 2 O have high dipole moments and fast (>10 −2 s −1 ) spontaneous de-excitation Nolt et al 1987) and para-H 18 2 O 1 11 −0 00 (at 1101.698256 GHz) towards Orion BN/KL (blue and red, respectively). The region of low-velocity HF absorption is highlighted in grey.…”

Section: First Detection Of Submm Absorption Towards Orionmentioning

confidence: 99%

Herschelobservations of EXtra-Ordinary Sources (HEXOS): Detection of hydrogen fluoride in absorption towards Orion KL

Phillips¹,

Bergin

Lis³

et al. 2010

A&A

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We report a detection of the fundamental rotational transition of hydrogen fluoride in absorption towards Orion KL using Herschel/HIFI. After the removal of contaminating features associated with common molecules ("weeds"), the HF spectrum shows a P-Cygni profile, with weak redshifted emission and strong blue-shifted absorption, associated with the low-velocity molecular outflow. We derive an estimate of 2.9 × 10 13 cm −2 for the HF column density responsible for the broad absorption component. Using our best estimate of the H 2 column density within the low-velocity molecular outflow, we obtain a lower limit of ∼1.6 × 10 −10 for the HF abundance relative to hydrogen nuclei, corresponding to ∼0.6% of the solar abundance of fluorine. This value is close to that inferred from previous ISO observations of HF J = 2−1 absorption towards Sgr B2, but is in sharp contrast to the lower limit of 6 × 10 −9 derived by Neufeld et al. for cold, foreground clouds on the line of sight towards G10.6-0.4.

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Accurate rotational constants of CO, HCl, and HF: Spectral standards for the 0.3- to 6-THz (10- to 200-cm−1) region

Cited by 151 publications

References 12 publications

Strong absorption by interstellar hydrogen fluoride:Herschel/HIFI observations of the sight-line to G10.6–0.4 (W31C)

Strong absorption by interstellar hydrogen fluoride:Herschel/HIFI observations of the sight-line to G10.6–0.4 (W31C)

Searches for HCl and HF in comets 103P/Hartley 2 and C/2009 P1 (Garradd) with theHerschelSpace Observatory

Herschelobservations of EXtra-Ordinary Sources (HEXOS): Detection of hydrogen fluoride in absorption towards Orion KL

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