Molecular dynamics simulations of D2O ice photodesorption

Arasa, C.; Andersson, Stefan; Cuppen, H. M.; Dishoeck, E. F. van; Kroes, Geert–Jan

doi:10.1063/1.3582910

Cited by 33 publications

(56 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…the discussion on O 2 and O 3 photodesorption upon VUV irradiation of O 2 ice in Zhen & Linnartz 2014). A number of theoretical studies (Galloway & Herbst 1994;Dzegilenko et al 1995;Andersson et al 2006;Andersson & van Dishoeck 2008;Arasa et al 2010Arasa et al , 2011Arasa et al , 2015van Hemert et al 2015) have focused on the molecular processes at play, confirming the high level of complexity involved.…”

Section: Introductionmentioning

confidence: 98%

A novel approach to measure photodesorption rates of interstellar ice analogues

Paardekooper

Fedoseev

Riedo

et al. 2016

A&A

View full text Add to dashboard Cite

Context. In recent years photodesorption rates have been determined in dedicated laboratory experiments for a number of different interstellar ice analogues. These rates are important in order to model non-thermal desorption processes that, for example, affect gas-phase abundances of species and determine the position of photo-induced snow lines in protoplanetary disks. However, different groups using similar experiments have found significant deviating photodesorption values. Aims. Here a new measurement concept is introduced that allows photodesorption rates to be determined following a different experimental approach. The potential of this method is demonstrated using the example of pure CO ice, the solid that gives the most striking discrepancies in the published results. Methods. The new experimental approach uses laser desorption post-ionisation time-of-flight mass spectrometry. It is based on the concept that the physical and geometrical properties of the plume obtained by laser induced desorption of the ice directly depend on the original ice thickness. This allows the ice loss to be determined as function of vacuum ultraviolet (VUV) fluence, which results in a photodesorption rate. The method has the additional advantage that it records all ice species, including photoproducts generated by the VUV irradiation. As a consequence, the method introduced here is also suited to determine the overall photodesorption rate of mixed ices. Results. The photodesorption rate for CO ice at 20 K has been determined as (1.4 ± 0.7) × 10 −3 molecules per incident VUV photon. This result is compared to existing experimental and theoretical values and the astronomical relevance is discussed.

show abstract

Section: Introductionmentioning

confidence: 98%

A novel approach to measure photodesorption rates of interstellar ice analogues

Paardekooper

Fedoseev

Riedo

et al. 2016

A&A

View full text Add to dashboard Cite

show abstract

“…As a first order approximation, the equivalent rates for the gas phase are used. This is likely over-estimating the grain-surface photodissociation rates, since the mechanisms for UV photodissociation and photodesorption of ices are now understood to be related as demonstrated in molecular dynamics studies (Andersson et al 2006;Andersson & van Dishoeck 2008;Arasa et al 2010Arasa et al , 2011Arasa et al , 2013Koning, Kroes & Arasa 2013) and experimental work (Bertin et al 2012;Fayolle et al 2013).…”

Section: Chemical Networkmentioning

confidence: 99%

Methanol along the path from envelope to protoplanetary disc

Drozdovskaya¹,

Walsh²,

Visser³

et al. 2014

Monthly Notices of the Royal Astronomical Society

106

View full text Add to dashboard Cite

Interstellar methanol is considered to be a parent species of larger, more complex organic molecules. A physicochemical simulation of infalling parcels of matter is performed for a low-mass star-forming system to trace the chemical evolution from cloud to disc. An axisymmetric 2D semi-analytic model generates the time-dependent density and velocity distributions, and full continuum radiative transfer is performed to calculate the dust temperature and the UV radiation field at each position as a function of time. A comprehensive gas-grain chemical network is employed to compute the chemical abundances along infall trajectories. Two physical scenarios are studied, one in which the dominant disc growth mechanism is viscous spreading, and another in which continuous infall of matter prevails. The results show that the infall path influences the abundance of methanol entering each type of disc, ranging from complete loss of methanol to an enhancement by a factor of ą 1 relative to the prestellar phase. Critical chemical processes and parameters for the methanol chemistry under different physical conditions are identified. The exact abundance and distribution of methanol is important for the budget of complex organic molecules in discs, which will be incorporated into forming planetary system objects such as protoplanets and comets. These simulations show that the comet-forming zone contains less methanol than in the precollapse phase, which is dominantly of prestellar origin, but also with additional layers built up in the envelope during infall. Such intriguing links will soon be tested by upcoming data from the Rosetta mission.

show abstract

“…The first constraints on the probability of this mechanism were obtained using Molecular Dynamics simulations (Andersson et al 2006;Arasa et al 2010Arasa et al , 2011. In these studies, the fate of photoproducts of water ice photodissociation-OH and H-were monitored in time.…”

Section: Reactive/chemical Desorptionmentioning

confidence: 99%

Grain Surface Models and Data for Astrochemistry

et al. 2017

Self Cite

View full text Add to dashboard Cite

The cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions.

show abstract

Molecular dynamics simulations of D2O ice photodesorption

Cited by 33 publications

References 53 publications

A novel approach to measure photodesorption rates of interstellar ice analogues

A novel approach to measure photodesorption rates of interstellar ice analogues

Methanol along the path from envelope to protoplanetary disc

Grain Surface Models and Data for Astrochemistry

Contact Info

Product

Resources

About