Millimeter emission from protoplanetary disks : dust, cold gas, and relativistic electrons
Salter, D.M.
Citation
Salter, D. M. (2010, November 25). Millimeter emission from protoplanetary disks : dust, cold
gas, and relativistic electrons. Leiden Observatory, Faculty of Science, Leiden University.Retrieved from https://hdl.handle.net/1887/16175
Version: Corrected Publisher’s Version
License: Licence agreement concerning inclusion of doctoral thesis in the Institutional Repository of the University of Leiden
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Millimeter Emission From Protoplanetary Disks
Dust, Cold Gas, and Relativistic Electrons
Millimeter Emission From Protoplanetary Disks
Dust, Cold Gas, and Relativistic Electrons
PROEFSCHRIFT
ter verkrijging van
de graad van Doctor aan de Universiteit Leiden,
op gezag van de Rector Magnificus Prof. Mr. P. F. van der Heijden, volgens besluit van het College voor Promoties
te verdedigen op donderdag 25 november 2010 klokke 11.15 uur
door
D. M. Salter
Promotiecommissie
Promotor: Prof. Dr. E. F. van Dishoeck Co-promotor: Dr. M. R. Hogerheijde
Overige leden: Prof. Dr. H. V. J. Linnartz (Leiden University / Vrije Universiteit Amsterdam) Prof. Dr. K. Kuijken (Leiden University)
Prof. Dr. C. Dominik (University of Amsterdam / Radboud University Nijmegen) Prof. Dr. G. A. Blake (California Institute of Technology)
Dr. L. Testi (European Southern Observatory)
Front Cover: An artist’s rendering of the birth of a star. Credit: NASA / JPL-Caltech / R. Hurt (SSC).
Contents
Page
Chapter1. Introduction 1
1.1 Origins . . . 2
1.1.1 The Formation of Sun-like Stars . . . 2
1.1.2 The Birth Sites of Planetary Systems . . . 4
1.2 The Study of Protoplanetary Disks . . . 8
1.2.1 Millimeter-wave Instrumentation . . . 8
1.2.2 The Dust. . . 10
1.2.3 Cold Gas . . . 13
1.2.4 Relativistic Electrons . . . 15
1.2.5 In the Laboratory . . . 17
1.3 This Thesis . . . 18
1.3.1 Outline of Chapters . . . 18
1.3.2 Main Results . . . 21
1.3.3 Outlook . . . 22
PartI The Dust and Gas Content Revealed with Millimeter Telescopes 29 Chapter2. A Single-dish Survey of the HCO+, HCN, and CN Emission Toward the T Tauri Disk Population in Taurus 31 2.1 Introduction . . . 32
2.2 Observations . . . 33
2.2.1 The Taurus Disk Sample . . . 33
2.2.2 JCMT Single-dish Millimeter Observations . . . 35
2.2.3 Data Reduction . . . 35
2.3 Results . . . 36
2.4 Trends . . . 38
2.5 Modeling the Molecular Emission . . . 45
2.5.1 Disk Models . . . 45
2.5.2 Comparison of Fixed-abundance Models . . . 47
2.5.3 The Specific Case of DG Tau . . . 50
2.5.4 Notes on Individual Sources . . . 54
2.6 Discussion . . . 56
2.7 Summary . . . 57
Chapter 3. Observing Low-J 12CO Transitions in Protoplanetary Disks with Varied Dust Properties 61 3.1 Introduction . . . 62
3.2 Observations . . . 63
viii Contents
3.2.1 The Disk Sample . . . 63
3.2.2 CARMA12CO (J = 1–0) Observations . . . 64
3.2.3 SMA12CO (J = 2–1) Observations . . . 64
3.3 Results . . . 65
3.3.1 CARMA 2.7 mm Continuum Data . . . 65
3.3.2 CARMA12CO (1–0) Line Data . . . 65
3.3.3 SMA 1.3 mm Continuum and12CO (2–1) Line Data . . . 68
3.4 Analysis . . . 69
3.4.1 CW Tau and IQ Tau . . . 69
3.4.2 DQ Tau . . . 69
3.4.3 V806 Tau . . . 73
3.4.4 V892 Tau . . . 74
3.5 Discussion . . . 75
3.6 Summary . . . 77
PartII Transient Flares of Non-thermal Millimeter Emission 81 Chapter4. Captured at Millimeter Wavelengths: a Flare from the Classical T Tauri Star DQ Tau 83 4.1 Introduction . . . 84
4.2 The DQ Tau System . . . 84
4.3 CARMA Observations . . . 85
4.4 Results and Analysis . . . 86
4.5 Discussion . . . 87
4.6 Conclusions . . . 89
Chapter5. Recurring Millimeter Flares as Evidence for Star-Star Magnetic Reconnection Events in the DQ Tau PMS Binary System 91 5.1 Introduction . . . 92
5.2 Observations and Data Reduction . . . 93
5.2.1 Millimeter Interferometry . . . 93
5.2.2 Optical Photometry . . . 95
5.3 Results and Analysis . . . 95
5.3.1 Millimeter Flare Properties . . . 95
5.3.2 Coincident Optical Brightenings . . . 101
5.4 Discussion . . . 103
5.4.1 Signatures of Synchrotron Emission . . . 103
5.4.2 De-polarization Effects . . . 105
5.4.3 Orientation and Topology of the Magnetospheres . . . 106
5.4.4 Optical Emission Mechanisms . . . 108
5.5 Conclusions . . . 109
A.1 Optical Data . . . 111
Chapter6. Hunting for Millimeter Flares from Magnetic Reconnection in Pre-main-sequence Spectroscopic Binaries 115 6.1 Introduction . . . 116
6.2 Observations . . . 117
6.2.1 Target Selection . . . 117
Contents ix
6.2.2 Observations and Data Reduction. . . 118
6.3 Results . . . 120
6.4 Discussion . . . 123
6.4.1 Event Statistics . . . 123
6.4.2 UZ Tau. . . 124
6.4.3 Other Sources . . . 126
6.5 Summary and Conclusions . . . 129
A.1 Millimeter and Optical Data . . . 131
PartIII Protoplanetary Dust Experiments in the Laboratory 139 Chapter7. A Zero-Gravity Instrument to Study Low Velocity Collisions of Fragile Particles at Low Temperatures 141 7.1 Introduction . . . 142
7.2 Experiment Design Overview . . . 143
7.2.1 Particle Storage and Cooling . . . 144
7.2.2 Cryogenic Operation . . . 146
7.2.3 Particle Acceleration System . . . 147
7.2.4 Removable Target Holder . . . 147
7.2.5 Data Acquisition and Imaging . . . 148
7.3 Performance in Microgravity . . . 150
7.4 Conclusions . . . 152
Nederlandse Samenvatting 155
Publication List 169
Curriculum Vitae 171
Acknowledgements 173
