Reaction Networks for Interstellar Chemical Modelling: Improvements and Challenges

By V. Wakelam, Ian W. M. Smith, E. Herbst, J. Troe, W. Geppert, H. Linnartz, K. Oberg, È. Roueff, M. Agúndez, P. Pernot and 3 more. 2010

211 citations recorded by the source corpus.

We survey the current situation regarding chemical modelling of the synthesis of molecules in the interstellar medium. The present state of knowledge concerning the rate coefficients and their uncertainties for the major gas-phase processes—ion-neutral reactions, neutral-neutral reactions, radiative association, and dissociative recombination—is reviewed. Emphasis is placed on those key reactions that have been identified, by sensitivity analyses, as ‘crucial’ in determining the predicted abundances of the species observed in the interstellar medium. These sensitivity analyses have been carried out for gas-phase models of three representative, molecule-rich, astronomical sources: the cold dense molecular clouds TMC-1 and L134N, and the expanding circumstellar envelope IRC +10216. Our review has led to the proposal of new values and uncertainties for the rate coefficients of many of the key reactions. The impact of these new data on the predicted abundances in TMC-1 and L134N is reported. Interstellar dust particles also influence the observed abundances of molecules in the interstellar medium. Their role is included in gas-grain, as distinct from gas-phase only, models. We review the methods for incorporating both accretion onto, and reactions on, the surfaces of grains in such models, as well as describing some recent experimental efforts to simulate and examine relevant processes in the laboratory. These efforts include experiments on the surface-catalyzed recombination of hydrogen atoms, on chemical processing on and in the ices that are known to exist on the surface of interstellar grains, and on desorption processes, which may enable species formed on grains to return to the gas-phase.

Subfields: Astronomy and Astrophysics, Atomic and Molecular Physics, and Optics, Physical and Theoretical Chemistry

View Paper: https://www.semanticscholar.org/paper/84d32ce1efd049f9a4ea9a594829a04034362559

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. R. Garrod
2. E. Herbst
3. V. Wakelam
4. E. Dishoeck
5. A. Tielens
6. M. Ruaud
7. H. Cuppen
8. C. Walsh

In Atomic and Molecular Physics, and Optics

1. R. Garrod
2. A. Tielens
3. E. Dishoeck
4. E. Herbst
5. V. Wakelam
6. S. Ioppolo
7. H. Cuppen
8. T. Lamberts

In Physical and Theoretical Chemistry

1. R. Garrod
2. E. Herbst
3. V. Wakelam
4. M. Ruaud
5. J. Loison
6. E. Dishoeck
7. A. Tielens
8. Jonathan Tennyson

Citations in the corpus

• A KINETIC DATABASE FOR ASTROCHEMISTRY (KIDA) (2012, methodology): “Large absolute values of correlation coefficients reveal strong influences of inputs on outputs (Wakelam et al. 2010b; Dobrijevic et al. 2010).”
• The UMIST database for astrochemistry 2012 (2012, methodology): “…et al. (2009), Vigren et al. (2010a), Vigren et al. (2010b), Vigren et al. (2010c), Vigren et al. (2012), Vikor et al. (1999), Wakelam et al. (2009), Wakelam et al. (2010a), Walsh et al. (2009), Whyte & Phillips (1983), Wilson et al. (1993), Wlodek et al. (1988), Woon & Herbst (1996), Xu et al.…”
• THE 2014 KIDA NETWORK FOR INTERSTELLAR CHEMISTRY (2015, background): “Because each study on a specific reaction can take from a few months to several years, such studies are best undertaken for systems identified as the most important ones (Wakelam et al. 2010).”
• The Molecular Universe (2011, background): “This is one area of research where we should focus our attention through close collaborations between astrochemical modelers and chemists (Wakelam et al. 2010).”
• Photodissociation and photoionisation of atoms and molecules of astrophysical interest (2017, background): “The sensitivity of a chemical network to its input rates and the propagating influence of specific rates to unrelated model species is studied in the context of interstellar and atmospheric chemistry (e.g., Wakelam et al. 2010; Loison et al. 2015).”
• Grain Surface Models and Data for Astrochemistry (2017, background): “The treatment of gas-phase chemistry has been described in a number of papers, including McElroy et al. (2013) and Wakelam et al. (2010).”