Formation rates of complex organics in UV irradiated CH3OH-rich ices I: Experiments

@article{Oberg2009FormationRO,
  title={Formation rates of complex organics in UV irradiated CH3OH-rich ices I: Experiments},
  author={Karin I. Oberg and Robin T. Garrod and E. F. van Dishoeck and Harold Linnartz},
  journal={Astronomy and Astrophysics},
  year={2009},
  volume={504},
  pages={891-913}
}
Context. Gas-phase complex organic molecules are commonly detected in the warm inner regions of protostellar envelopes, so-called hot cores. Recent models show that photochemistry in ices followed by desorption may explain the observed abundances. There is, however, a general lack of quantitative data on UV-induced complex chemistry in ices. Aims. This study aims to experimentally quantify the UV-induced production rates of complex organics in CH3OH-rich ices under a variety of astrophysically… 
THE EFFECT OF H2O ON ICE PHOTOCHEMISTRY
UV irradiation of simple ices is proposed to efficiently produce complex organic species during star formation and planet formation. Through a series of laboratory experiments, we investigate the
Radical-induced chemistry from VUV photolysis of interstellar ice analogues containing formaldehyde
Surface processes and radical chemistry within interstellar ices are increasingly suspected to play an important role in the formation of complex organic molecules (COMs) observed in several
UV photoprocessing of CO2 ice: a complete quantification of photochemistry and photon-induced desorption processes
Ice mantles that formed on top of dust grains are photoprocessed by the secondary ultraviolet (UV) field in cold and dense molecular clouds. UV photons induce photochemistry and desorption of ice
Study of the photon-induced formation and subsequent desorption of CH3OH and H2CO in interstellar ice analogs
Context. Methanol and formaldehyde are two simple organic molecules that are ubiquitously detected in the interstellar medium, in both the solid and gaseous phases. An origin in the solid phase and a
Photochemistry of the PAH pyrene in water ice: the case for ion-mediated solid-state astrochemistry
Context. Icy dust grains play an important role in the formation of complex molecules in the interstellar medium (ISH). Laboratory studies have mainly focused on the physical interactions and
Radical recombination in interstellar ices, a not so simple mechanism.
TLDR
This work aims to study the dimerisation of formyl radical HC˙O using a cryogenic matrix technique and indicates that the reaction of one HC�’O with another does not lead to the direct formation of glyoxal but yields H2CO and CO.
Surface formation of hcooh at low temperature
The production of formic acid (HCOOH) in cold and hot regions of the interstellar medium is not well understood. Recent gas-phase experiments and gas-grain models hint at a solid-state production
H2 chemistry in interstellar ices: the case of CO ice hydrogenation in UV irradiated CO:H2 ice mixtures
Context. In dense clouds, hydrogenation reactions on icy dust grains are key in the formation of molecules, like formaldehyde, methanol, and complex organic molecules (COMs). These species form
Combined IR and XPS characterization of organic refractory residues obtained by ion irradiation of simple icy mixtures
Context. Multi-year laboratory experiments have demonstrated that frozen icy mixtures containing simple organic and inorganic molecules (such as H2O, N2, CH4, CO, CO2, C2H6, etc.), if exposed to a
Negligible photodesorption of methanol ice and active photon-induced desorption of its irradiation products
Context. Methanol is a common component of interstellar and circumstellar ice mantles and is often used as an evolution indicator in star-forming regions. The observations of gas-phase methanol in
...
...

References

SHOWING 1-10 OF 76 REFERENCES
Photodesorption of ices I: CO, N₂, and CO₂
Context. A longstanding problem in astrochemistry is how molecules can be maintained in the gas phase in dense inter- and circumstellar regions at temperatures well below their thermal desorption
An experimental study of the organic molecules produced in cometary and interstellar ice analogs by thermal formaldehyde reactions.
TLDR
It is estimated that about 1% of the organics found in the coma of Comet Halley could have been produced by thermal formaldehyde reactions taking place in the nucleus.
H-atom bombardment of CO2, HCOOH, and CH3CHO containing ices
Context. Hydrogenation reactions are expected to be among the most important surface reactions on interstellar ices. However, solid state astrochemical l aboratory data on reactions of H-atoms with
Mechanistical Studies on the Irradiation of Methanol in Extraterrestrial Ices
Pure ices of amorphous methanol, CH3OH(X 1A'), were irradiated at 11 K by 5 keV electrons at 100 nA for 1 hr. These energetic electrons simulate electronic energy transfer processes that occur as
Photodesorption of water ice - A molecular dynamics study
Context. Absorption of ultraviolet radiation by water ice coating interstellar grains can lead to dissociation and desorption of the ice molecules. These processes are thought to be important in the
PHOTODESORPTION OF ICES. II. H2O AND D2O
Gaseous H2O has been detected in several cold astrophysical environments, where the observed abundances cannot be explained by thermal desorption of H2O ice or by H2O gas-phase formation. These
UV-photoprocessing of interstellar ice analogs: New infrared spectroscopic results
We simulate experimentally the physical conditions present in dense clouds by means of a high vacuum experimental setup at low temperature T ≈ 12 K. The accretion and photoprocessing of ices on grain
Laboratory Studies of the Formation of Methanol and Other Organic Molecules by Water+Carbon Monoxide Radiolysis: Relevance to Comets, Icy Satellites, and Interstellar Ices
Radiation processing of cometary, planetary, and interstellar ices has been investigated by irradiating mixtures of H2O and CO near 16 K with 0.8-MeV protons. IR spectroscopy and isotopic
PHOTODESORPTION OF CO ICE
At the high densities and low temperatures found in star forming regions, all molecules other than H2 should stick on dust grains on timescales shorter than the cloud lifetimes. Yet these clouds are
...
...