Cover Page The handle http://hdl.handle.net/1887/33044 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: 2015-05-20
Unraveling the surface formation of regular and deuterated water in space A combined laboratory and computational study Thanja Lamberts
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: 978-94-6259-678-8 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).
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
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
Voor Hetty en Timo
C O N T E N T S 1 introduction 1 1.1 Water during the various stages of star formation 2 1.2 Ices in the interstellar medium 3 1.3 Solid state water formation: surface chemistry 4 1.4 Origin of water on Earth: HDO 5 1.5 This thesis 7 2 methods: experimental solid-state astrochemistry 11 2.1 Introduction 12 2.2 Deposition and processing of ices 12 2.2.1 Surfaces 12 2.2.2 Ice deposition 13 2.2.3 Ice processing 13 2.3 Analytical techniques 16 2.3.1 Infrared spectroscopy 16 2.3.2 Temperature Programmed Desorption 17 2.3.3 Mass spectrometry 18 2.3.4 Other analytical techniques 19 2.4 SURFRESIDE 2 - system description 19 2.4.1 Main Chamber 20 2.4.2 Analytical Tools 21 2.4.3 Data Analysis 22 2.4.4 Atom Beam Lines 23 2.4.5 Beam Flux Determinations 26 3 methods: kinetic monte carlo 35 3.1 Introduction 36 3.2 Historical and theoretical overview of grain modeling techniques 38 3.2.1 Rate equations 38 3.2.2 Master equation method 39 3.2.3 Macroscopic Kinetic Monte Carlo 40 3.2.4 Microscopic Kinetic Monte Carlo 42 3.3 Technical aspects of microscopic KMC 43 3.3.1 Representation of the grain 43 3.3.2 Input parameters in grain models: filling the table of events 43 3.3.3 Kinetic Monte Carlo algorithms 46 3.3.4 Simulations with varying rates 47 3.4 KMC simulations of astrochemically relevant ice (analogs) 49 3.4.1 Simulations of ice experiments 49 3.4.2 Simulations of astrochemical environments 49 3.5 New directions 51
4 water formation at low temperatures by surface o 2 hydrogenation monte carlo simulation 57 4.1 Introduction 58 4.2 Experimental observations 59 4.3 The Monte Carlo method 61 4.3.1 Deposition of an O 2 surface 61 4.3.2 Sequential hydrogenation 62 4.3.3 Co-deposition 65 4.3.4 Size and ice morphology 65 4.4 Results and Discussion 66 4.4.1 Standard simulations 66 4.4.2 Key reactions 69 4.4.3 Penetration depth 75 4.5 Recommendations for future studies 76 4.5.1 Best fit 77 4.5.2 Astrochemical Considerations 79 4.5.3 Practical use of the best fit parameters 80 4.6 Conclusions 80 5 the formation of ice mantles on interstellar grains revisited the effect of exothermicity 85 5.1 Introduction 86 5.2 Methodology 87 5.2.1 Adaptations of the Monte Carlo routine 90 5.2.2 Experimental vs. Interstellar simulations 91 5.3 Simulations of experiments 92 5.4 Simulations of interstellar conditions 96 5.4.1 Diffuse clouds 96 5.4.2 Translucent clouds 99 5.4.3 Dense clouds 100 5.4.4 Comparison to observations and other models 101 5.5 Discussions and conclusions 102 6 relevance of the h 2 + o pathway for the surface formation of interstellar water 105 6.1 Introduction 106 6.2 Calculation of the reaction rate 106 6.3 Experiments 108 6.3.1 Methods 108 6.3.2 Results and discussion 110 6.4 Theoretical 115 6.4.1 Kinetic Monte Carlo model 115 6.4.2 Experimental modeling 115 6.4.3 Astrochemical modeling 117 6.5 Astrophysical Implications 119 6.6 Conclusions 121
7 thermal h/d exchange in polar ice deuteron scrambling in space 123 7.1 Introduction 124 7.2 Methods 126 7.2.1 Experimental 127 7.2.2 Spectral Fitting 130 7.2.3 Reaction dynamics 132 7.2.4 Optimization procedure 132 7.3 Results and Discussion 133 7.3.1 Activation energy of proton exchange in H 2 O:D 2 O mixtures 133 7.3.2 Proton exchange in other hydrogen bonded molecules 135 7.4 Experimental Conclusions 136 7.5 Astrochemical Implications 137 7.5.1 Protostellar and protoplanetary environments 137 7.5.2 Cometary ices 138 7.5.3 Proof-of-principle modeling 138 8 low-temperature chemistry between water and the hydroxyl radical h/d isotopic effects 143 8.1 Introduction 144 8.2 Experimental Methods 145 8.3 Results and Discussion 147 8.4 Astrochemical Implications 151 8.5 Conclusions 153 samenvatting 157 list of publications 161 curriculum vitae 163 dankwoord 165
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