Detection of interstellar H3O(+) - A confirming line

Wootten, Alwyn; Mangum, J. G.; Turner, B. E.; Bogey, M.; Boulanger, F.; Combes, F.; Encrenaz, P.; Gérin, M.

doi:10.1086/186178

Cited by 64 publications

(53 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We are unable to confirm previous tentative detections of H 3 O + toward Orion KL (Hollis et al 1986;Wootten et al 1986;Wootten et al 1991;Phillips et al 1992;Timmermann et al 1996;Lerate et al 2006). Of these, Phillips et al (1992) present the best evidence: 3 emission lines at 307, 364, and 396 GHz, lying 45, 85, and 105 cm −1 above ground; but they do not rule out the possibility of blends with other lines.…”

Section: Discussioncontrasting

confidence: 91%

Detection of OH⁺and H₂O⁺towards Orion KL

Gupta¹,

Rimmer

Pearson³

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

We report observations of the reactive molecular ions OH + , H 2 O + , and H 3 O + towards Orion KL with Herschel/HIFI. All three N = 1−0 finestructure transitions of OH + at 909, 971, and 1033 GHz and both fine-structure components of the doublet ortho-H 2 O + 1 11 −0 00 transition at 1115 and 1139 GHz were detected; an upper limit was obtained for H 3 O + . OH + and H 2 O + are observed purely in absorption, showing a narrow component at the source velocity of 9 km s −1 , and a broad blueshifted absorption similar to that reported recently for HF and para-H 18 2 O, and attributed to the low velocity outflow of Orion KL. We estimate column densities of OH + and H 2 O + for the 9 km s −1 component of 9±3×10 12 cm −2 and 7± 2× 10 12 cm −2 , and those in the outflow of 1.9± 0.7× 10 13 cm −2 and 1.0± 0.3× 10 13 cm −2 . Upper limits of 2.4× 10 12 cm −2 and 8.7× 10 12 cm −2 were derived for the column densities of ortho and para-H 3 O + from transitions near 985 and 1657 GHz. The column densities of the three ions are up to an order of magnitude lower than those obtained from recent observations of W31C and W49N. The comparatively low column densities may be explained by a higher gas density despite the assumption of a very high ionization rate.

show abstract

Section: Discussioncontrasting

confidence: 91%

Detection of OH⁺and H₂O⁺towards Orion KL

Gupta¹,

Rimmer

Pearson³

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…Typically, gas-phase reaction models have a very steep inverse temperature dependence in their reaction rates. A temperature of $200 K should, for example, reduce the ratio predicted by Wootten et al (1992) to less than 0.01, which would put the prediction for W51e2 even further from our observed values for the CH 3 COOH/HCOOCH 3 abundance ratio. The second problem is that many of the radiative association rate coefficients are not well determined.…”

Section: Formation Of Acetic Acidmentioning

confidence: 43%

“…This gives a CH 3 COOH/HCOOCH 3 abundance ratio of $0.07. Wootten et al (1992) used the same radiative association approach with a slightly different set of assumptions to predict a CH 3 COOH/HCOOCH 3 ratio of $0.1 at a gas temperature of 30 K, but the ratio drops to $0.01 at 100 K. We note three problems associated with these radiative association predictions of the acetic acid and methyl formate abundances. The first problem is that the abundance ratios determined from our observations are larger than the high-temperature radiative association predictions (T rot > 100 K).…”

Section: Formation Of Acetic Acidmentioning

confidence: 99%

See 1 more Smart Citation

Acetic Acid in the Hot Cores of Sagitarrius B2(N) and W51

Remijan

Snyder

Liu

et al. 2002

ApJ

View full text Add to dashboard Cite

We have detected interstellar acetic acid (CH 3 COOH) toward the hot core source W51e2. This is the first new source of interstellar CH 3 COOH since its discovery by Mehringer et al. toward the hot core source Sgr B2(N-LMH). In this paper, we report CH 3 COOH observations at two new frequencies toward Sgr B2(N-LMH) with the OVRO array and at 10 frequencies toward W51e2 with the Berkeley-Illinois-Maryland Association array. Toward Sgr B2(N-LMH) the agreement in positions, intensities, and velocities between the two lines from the previous study and the two new lines strongly indicates that all four CH 3 COOH lines are coming from a common source. Using all four detected transitions, we find an average column density of 6:1ð6Þ Â 10 15 cm À2 , a fractional abundance of ð0:8 6Þ Â 10 À10 relative to H 2 and ð3 6Þ Â 10 À2 relative to its isomer methyl formate (HCOOCH 3 ). Toward W51e2, we find a CH 3 COOH column density of 1:7ð5Þ Â 10 16 cm À2 with a fractional abundance of 1:7 Â 10 À9 relative to H 2 and ð1 6Þ Â 10 À2 relative to HCOOCH 3 . Furthermore, we find the distribution of CH 3 COOH toward W51e2 is coincident with HCOOCH 3 , thus suggesting a similar formation mechanism.

show abstract

“…Ions containing oxygen and hydrogen are formed in interstellar clouds [4], and they are assumed to play an important role in gas phase chemical routes leading to the production of H 2 O. The hydronium ion (H 3 O + ) has been observed in molecular clouds since the nineties [5]. The recent Herschel mission has led to the detection of OH + [6] and H 2 O + [7] in the diffuse interstellar medium and their role as markers of regions with a small fraction of H 2 has been highlighted [8].…”

Section: Introductionmentioning

confidence: 99%

Chemistry in glow discharges of H₂/O₂mixtures: diagnostics and modelling

Jiménez-Redondo¹,

Carrasco²,

Herrero³

et al. 2015

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

The chemistry of low pressure H 2 + O 2 discharges with different mixture ratios has been studied in a hollow cathode DC reactor. Neutral and positive ion distributions have been measured by mass spectrometry, and Langmuir probes have been used to provide charge densities and electron temperatures. A simple zero order kinetic model including neutral species and positive and negative ions, which takes into account gas-phase and heterogeneous chemistry, has been used to reproduce the global composition of the plasmas over the whole range of mixtures experimentally studied, and allows for the identification of the main physicochemical mechanisms that may explain the experimental results. To our knowledge, no combined experimental and modelling studies of the heavy species kinetics of low pressure H 2 + O 2 plasmas including ions has been reported before.As expected, apart from the precursors, H 2 O is detected in considerable amounts. The model also predicts appreciable concentrations of H and O atoms and the OH radical. The relevance of the metastable species O( 1 D) and O 2 (a 1 Δ g ) is analysed. Concerning the charged species, positive ion distributions are dominated by H 3 O + for a wide range of intermediate mixtures, while H 3 + and O 2 + are the major ions for the higher and lower H 2 /O 2 ratios, respectively. The mixed ions OH + , H 2 O + and HO 2 + are also observed in small amounts. Negative ions are shown to have a limited relevance in the global chemistry; their main contribution is the reduction of the electron density available for electron impact processes.

show abstract

Detection of interstellar H3O(+) - A confirming line

Cited by 64 publications

References 0 publications

Detection of OH⁺and H₂O⁺towards Orion KL

Detection of OH⁺and H₂O⁺towards Orion KL

Acetic Acid in the Hot Cores of Sagitarrius B2(N) and W51

Chemistry in glow discharges of H₂/O₂mixtures: diagnostics and modelling

Contact Info

Product

Resources

About

Detection of interstellar H3O(+) - A confirming line

Cited by 64 publications

References 0 publications

Detection of OH+and H2O+towards Orion KL

Detection of OH+and H2O+towards Orion KL

Acetic Acid in the Hot Cores of Sagitarrius B2(N) and W51

Chemistry in glow discharges of H2/O2mixtures: diagnostics and modelling

Contact Info

Product

Resources

About

Detection of OH⁺and H₂O⁺towards Orion KL

Detection of OH⁺and H₂O⁺towards Orion KL

Chemistry in glow discharges of H₂/O₂mixtures: diagnostics and modelling