Cover Page. The handle holds various files of this Leiden University dissertation.

Transcription

1 Cover Page The handle holds various files of this Leiden University dissertation. Author: Lamberts, Agneta Luciana Matthanja (Thanja) Title: Unraveling the surface formation of regular and deuterated water in space : a combined laboratory and computational study Issue Date:

2 Unraveling the surface formation of regular and deuterated water in space A combined laboratory and computational study Thanja Lamberts

3 c Thanja Lamberts 2015 Niets uit deze uitgave mag worden verveelvoudigd, opgeslagen in een geautomatiseerd gegevensbestand of openbaar gemaakt worden in enige vorm of op enige wijze zonder voorafgaande schriftelijke toestemming van de auteur. Unraveling the surface formation of regular and deuterated water in space A combined laboratory and computational study, Thesis, Leiden University Ontrafelen van de oppervlaktevorming van gewoon en gedeutereerd water in de ruimte Een gecombineerde laboratorium en computationele studie, Proefschrift, Universiteit Leiden 168 pages; illustrated, with bibliographic references and summary in Dutch isbn/ean: Printed by Ipskamp Drukkers Cover design by Gaetano Fiorin and Thanja Lamberts This work has been financially supported by the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (nwo) and by the European Research Council (erc).

4 Unraveling the surface formation of regular and deuterated water in space A combined laboratory and computational study Proefschrift ter verkrijging van de graad van doctor aan de Universiteit Leiden op gezag van de Rector Magnificus prof. mr. C. J. J..M. Stolker, volgens besluit van het College voor Promoties te verdedigen op woensdag 20 mei 2015 klokke 13:45 uur door Agneta Luciana Matthanja Lamberts geboren te s Gravenhage in 1987

5 Promotiecommissie Promotor Prof. dr. H. V. J. Linnartz Co-promotores Dr. H. M. Cuppen Radboud Universiteit Nijmegen Dr. S. Ioppolo The Open University Overige leden Prof. dr. H. J. A. Röttgering Prof. dr. A. G. G. M. Tielens Prof. dr. G. C. Groenenboom Prof. dr. N. J. Mason Dr. D. A. Semenov Radboud Universiteit Nijmegen The Open University Max Planck Institute for Astronomy

6 Voor Hetty en Timo

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8 C O N T E N T S 1 introduction Water during the various stages of star formation Ices in the interstellar medium Solid state water formation: surface chemistry Origin of water on Earth: HDO This thesis 7 2 methods: experimental solid-state astrochemistry Introduction Deposition and processing of ices Surfaces Ice deposition Ice processing Analytical techniques Infrared spectroscopy Temperature Programmed Desorption Mass spectrometry Other analytical techniques SURFRESIDE 2 - system description Main Chamber Analytical Tools Data Analysis Atom Beam Lines Beam Flux Determinations 26 3 methods: kinetic monte carlo Introduction Historical and theoretical overview of grain modeling techniques Rate equations Master equation method Macroscopic Kinetic Monte Carlo Microscopic Kinetic Monte Carlo Technical aspects of microscopic KMC Representation of the grain Input parameters in grain models: filling the table of events Kinetic Monte Carlo algorithms Simulations with varying rates KMC simulations of astrochemically relevant ice (analogs) Simulations of ice experiments Simulations of astrochemical environments New directions 51

9 4 water formation at low temperatures by surface o 2 hydrogenation monte carlo simulation Introduction Experimental observations The Monte Carlo method Deposition of an O 2 surface Sequential hydrogenation Co-deposition Size and ice morphology Results and Discussion Standard simulations Key reactions Penetration depth Recommendations for future studies Best fit Astrochemical Considerations Practical use of the best fit parameters Conclusions 80 5 the formation of ice mantles on interstellar grains revisited the effect of exothermicity Introduction Methodology Adaptations of the Monte Carlo routine Experimental vs. Interstellar simulations Simulations of experiments Simulations of interstellar conditions Diffuse clouds Translucent clouds Dense clouds Comparison to observations and other models Discussions and conclusions relevance of the h 2 + o pathway for the surface formation of interstellar water Introduction Calculation of the reaction rate Experiments Methods Results and discussion Theoretical Kinetic Monte Carlo model Experimental modeling Astrochemical modeling Astrophysical Implications Conclusions 121

10 7 thermal h/d exchange in polar ice deuteron scrambling in space Introduction Methods Experimental Spectral Fitting Reaction dynamics Optimization procedure Results and Discussion Activation energy of proton exchange in H 2 O:D 2 O mixtures Proton exchange in other hydrogen bonded molecules Experimental Conclusions Astrochemical Implications Protostellar and protoplanetary environments Cometary ices Proof-of-principle modeling low-temperature chemistry between water and the hydroxyl radical h/d isotopic effects Introduction Experimental Methods Results and Discussion Astrochemical Implications Conclusions 153 samenvatting 157 list of publications 161 curriculum vitae 163 dankwoord 165

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12 A C R O N Y M S AKMC Adaptive Kinetic Monte Carlo CEM Channel Electron Multiplier CTRW Continuous-Time Random-Walk DAN Dutch Astrochemistry Network ER Eley-Rideal FTIR Fourier Transform InfraRed HA Hot-Atom HABS Hydrogen Atom Beam Source HIFI Heterodyne Instrument for the Far-Infrared HSO Herschel Space Telescope IRF Interstellar Radiation Field ISM InterStellar Medium ISO Infrared Space Observatory JFC Jupiter Family Comet KMC Kinetic Monte Carlo LASSIE Laboratory Astrochemical Surface Science In Europe LH Langmuir-Hinshelwood MALDI Matrix-Assisted Laser Desorption/Ionization MWAS MicroWave Atom Source OCC Oort Cloud Comet QCM Quartz Crystal Microbalance QMS Quadrupole Mass Spectrometer RAIR Reflection Absorption InfraRed REMPI Resonance Enhanced Multiphoton Ionization SEM Secondary Electron Multiplier SMOW Standard Mean Ocean Water SST Spitzer Space Telescope SURFRESIDE Surface REaction SImulation DEvice TOF Time Of Flight TPD Temperature Programmed Desorption UHV Ultra High Vacuum WISH Water In Star-forming regions with Herschel YSO Young Stellar Object

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