Ions in grain mantles - The 4.62 micron absorption by OCN(-) in W33A

Grim, R. J. A.; Greenberg, J. Mayo

doi:10.1086/185012

Cited by 150 publications

(133 citation statements)

References 0 publications

Supporting

Mentioning

124

Contrasting

Order By: Relevance

“…In many cases, an absorption band results which is remarkably similar to that seen in the interstellar medium in both proÐle and peak position (Moore et al 1983 ;Lacy et al 1984 ;Grim & Greenberg 1987 ;Tegler et al 1993 ;Schutte & Greenberg 1997 ;Demyk et al 1998 ;Palumbo et al 2000 ;Hudson & Moore 2000). Here we report irradiation experiments using ion bombardment of and ices.…”

Section: Introductionmentioning

confidence: 56%

Hydrogen Isotopic Substitution Studies of the 2165 Wavenumber (4.62 Micron) “XCN” Feature Produced by Ion Bombardment

Palumbo

Pendleton

Strazzulla

2000

ApJ

View full text Add to dashboard Cite

The interstellar 4.62 km absorption band, commonly seen toward embedded protostellar objects, has not yet been unambiguously identiÐed ; here we report new results which further elucidate the components of the band carrier, which is often referred to in the literature as the "" XCN ÏÏ band due to previous implications of carbon and nitrogen. If the atmosphere of the early Earth was not overly reducing, as some studies indicate, production of prebiotic molecules containing the cyanogen bond would have been difficult. In that case, CN-bearing molecules, necessary for the origin of life, may have come primarily from extraterrestrial sources, and the interstellar medium may be an important source of those molecules. Laboratory studies show that energetic processing of ice mixtures containing H, C, N, and O atoms readily reproduce a band similar in peak position and proÐle to that seen in the interstellar spectra. Earlier isotopic labeling experiments clearly identiÐed carbon, nitrogen, and oxygen as active participants of the XCN species. In this paper, results of ion bombardment of and CH 3 OH : N 2 ices are presented. A shift in band position resulting from deuterium substitution demon-CD 3 OD : N 2 strates that hydrogen is also a component of the carrier in the laboratory-produced 4.62 km band. Irradiation of ices through ion bombardment allows the testing of mixtures which include a possible N 2 , source of the available nitrogen in dense cloud ices that cannot be probed through UV photolysis experiments.

show abstract

Section: Introductionmentioning

confidence: 56%

Hydrogen Isotopic Substitution Studies of the 2165 Wavenumber (4.62 Micron) “XCN” Feature Produced by Ion Bombardment

Palumbo

Pendleton

Strazzulla

2000

ApJ

View full text Add to dashboard Cite

show abstract

“…Other molecules can be produced on the grain surface by successive hydrogenation of condensed species and/or interaction with low-energy cosmic rays and UV photons (e.g. Tielens & Hagen 1982;Grim & Greenberg 1987;Palumbo & Strazzulla 1993). The radiation field modifies the pristine ices ionizing the molecules and producing radicals that after recombination can form new species.…”

Section: Introductionmentioning

confidence: 99%

Formation of methyl formate after cosmic ion irradiation of icy grain mantles

Modica¹,

Palumbo²

2010

A&A

102

View full text Add to dashboard Cite

Context. Methyl formate (HCOOCH 3 ) is a complex organic molecule detected in hot cores and hot corinos. Gas-phase chemistry fails to reproduce its observed abundance, which usually varies between 10 −7 and 10 −9 with respect to H 2 . Aims. Laboratory experiments were performed in order to investigate a solid-state route of methyl formate formation, to obtain an estimate of the amount that can be formed, and to verify whether it can account for the observed abundances. Methods. Several solid samples (16 K) of astrophysical interest were analyzed by infrared spectroscopy in the 4400−400 cm −1 range. The infrared spectral characteristics of frozen methyl formate were studied by deriving their band strength values. The effects produced upon warm-up of the samples were analyzed comparing the spectra taken at different temperatures. In order to study the formation and destruction mechanism of methyl formate in the interstellar ices, a binary mixture of methanol (CH 3 OH) and carbon monoxide (CO) ice and a sample of pure methanol were irradiated at 16 K with 200 keV protons. Methyl formate was identified through its fundamental mode (CH 3 rocking) at about 1160 cm −1 . Results. We present the mid-infrared methyl formate ice spectrum showing both the amorphous (16 K) and the crystalline (110 K) structure. We report novel measurements of the band strength values of the six main methyl formate bands. We prove the formation and the destruction of methyl formate after irradiation of CH 3 OH and a CO:CH 3 OH mixture. Extrapolating our results to the interstellar medium conditions we found that the production timescale of methyl formate agrees well with the evolutionary time of molecular clouds. The comparison with the observational data indicates that the amount of methyl formate formed after irradiation can account for the observed abundances. Conclusions. The present results allow us to suggest that gas phase methyl formate observed in dense molecular clouds is formed in the solid state after cosmic ion irradiation of icy grain mantles containing CO and CH 3 OH and released to the gas phase after desorption of icy mantles.

show abstract

“…The spectra of several protostellar objects exhibit a strong absorption feature at 4.62 microns (2165 cm −1 ), called the XCN band, which is commonly attributed to the solid-phase cyanate ion OCN − (Grim & Greenberg 1987;Lowenthal et al 2000;Novozamsky et al 2001;van Broekhuizen et al 2005). A systematic study of this feature with the VLT-ISAAC spectrometer shows large source-to-source abundance variations (van Broekhuizen et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Kinetics of the OCN⁻and HOCN formation from the HNCO + H₂O thermal reaction in interstellar ice analogs

Theulé

Duvernay

Ilmane

et al. 2011

A&A

View full text Add to dashboard Cite

Aims. We study in the laboratory the kinetics of the low-temperature OCN − and HOCN formation from the purely thermal reaction of solid HNCO and H 2 O. The cyanate ion OCN − is an intermediate in the isomerization process of isocyanic acid HNCO into cyanic acid HOCN in water ice. Methods. We study the reaction, isomerization and desorption kinetics of the HNCO/OCN − /HOCN system using Fourier transform infrared spectroscopy. Results. Activation energies of 26 ± 2 kJ mol −1 (3127 K) and 36 ± 1 kJ mol −1 (4330 K) are found for the HNCO + H 2 O → OCN − + H 3 O + and OCN − + H 3 O + → HOCN + H 2 O reactions respectively. Desorption energies of 37 ± 3 kJ mol −1 (4450 K) and 40 ± 3 kJ mol −1 (4811 K) are measured for HNCO and OCN − , respectively. Conclusions. The present experiment has the important implication that the H 2 O + HNCO reaction alone cannot account for the observed abundances of solid OCN − in astronomical IR sources.

show abstract

Ions in grain mantles - The 4.62 micron absorption by OCN(-) in W33A

Cited by 150 publications

References 0 publications

Hydrogen Isotopic Substitution Studies of the 2165 Wavenumber (4.62 Micron) “XCN” Feature Produced by Ion Bombardment

Hydrogen Isotopic Substitution Studies of the 2165 Wavenumber (4.62 Micron) “XCN” Feature Produced by Ion Bombardment

Formation of methyl formate after cosmic ion irradiation of icy grain mantles

Kinetics of the OCN⁻and HOCN formation from the HNCO + H₂O thermal reaction in interstellar ice analogs

Contact Info

Product

Resources

About

Ions in grain mantles - The 4.62 micron absorption by OCN(-) in W33A

Cited by 150 publications

References 0 publications

Hydrogen Isotopic Substitution Studies of the 2165 Wavenumber (4.62 Micron) “XCN” Feature Produced by Ion Bombardment

Hydrogen Isotopic Substitution Studies of the 2165 Wavenumber (4.62 Micron) “XCN” Feature Produced by Ion Bombardment

Formation of methyl formate after cosmic ion irradiation of icy grain mantles

Kinetics of the OCN−and HOCN formation from the HNCO + H2O thermal reaction in interstellar ice analogs

Contact Info

Product

Resources

About

Kinetics of the OCN⁻and HOCN formation from the HNCO + H₂O thermal reaction in interstellar ice analogs