Cover Page
The following handle holds various files of this Leiden University dissertation:
http://hdl.handle.net/1887/61006
Author: Miotello, A.
Title: The puzzle of protoplanetary disk masses
Issue Date: 2018-03-07
The puzzle
of protoplanetary disk masses
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 7 maart 2018
klokke 11:15 uur
door
Anna Miotello
geboren te Gallarate, Italie in 1988
Promotiecommissie
Promotor Prof. dr. E. F. van Dishoeck
Co-promotor Dr. L. Testi ESO/INAF
Overige leden Prof. dr. E. A. Bergin University of Michigan Prof. dr. I. Kamp Rijksuniversiteit Groningen Prof. dr. I. Pascucci University of Arizona Prof. dr. H. J. A. R ¨ottgering
Prof. dr. A. G. G. M. Tielens
ISBN: 978-94-028-0940-4
Cover design by Laura Somaglino.
To my gang Carlo, Caterina, Ambrogio and Monica
C ONTENTS
Chapter 1: Introduction 1
1.1 Star formation and protoplanetary disks . . . 2
1.2 The Atacama Large Millimeter/submillimeter Array . . . 7
1.3 Disk dust mass determination . . . 9
1.4 Disk gas mass determination . . . 11
1.4.1 H2, the main gaseous component . . . 12
1.4.2 Gas masses from HD observations . . . 12
1.4.3 CO as gas mass tracer . . . 14
1.5 Physical-chemical modeling . . . 17
1.5.1 DALI . . . 17
1.6 This thesis and future outlook . . . 19
Chapter 2: Protoplanetary disk masses from CO isotopologues line emission 23 2.1 Introduction . . . 25
2.2 Model . . . 27
2.2.1 Isotope-selective processes . . . 28
2.2.2 Chemical network . . . 30
2.2.3 Parameters of the disk model . . . 31
2.2.4 Grid of models . . . 32
2.3 Results . . . 33
2.3.1 Abundances . . . 33
2.3.2 Line fluxes . . . 40
2.3.3 Line optical depth . . . 43
2.4 Discussion . . . 44
2.4.1 Beam convolutions . . . 44
2.4.2 Mass estimates . . . 47
2.4.3 TW Hya . . . 48
2.5 Summary and conclusions . . . 52
Chapter 3: Determining protoplanetary disk gas masses from CO isotopo-
logues line observations 55
3.1 Introduction . . . 57
3.2 Model . . . 58
3.2.1 Physical structure . . . 59
3.2.2 Chemical network . . . 60
3.2.3 Grid of models . . . 61
3.3 Results . . . 65
3.3.1 Abundances . . . 65
3.3.2 Line intensities . . . 66
3.4 Discussion . . . 75
3.4.1 Comparison with parametric models . . . 75
3.4.2 Analysis of CO isotopologues observations . . . 79
3.4.3 Complementary tracers: [OI], [CI], and [CII] . . . 79
3.4.4 Effects of lower carbon abundance . . . 80
3.5 Summary and Conclusion . . . 81
Appendices 3.A Additional tables and figures . . . 84
3.B Effects of carbon depletion on CO isotopologue line intensities . . . 93
Chapter 4: Lupus disks with faint CO isotopologues: low gas/dust or high carbon depletion? 99 4.1 Introduction . . . 101
4.2 ALMA observations . . . 103
4.3 Model . . . 103
4.4 Results . . . 104
4.4.1 Dust masses revisited . . . 104
4.4.2 Gas masses . . . 108
4.5 Discussion . . . 112
4.5.1 Gas-to-dust ratio . . . 112
4.5.2 Carbon depletion vs low gas masses . . . 113
4.5.3 Correlation between disk gas mass and stellar mass . . . 116
4.6 Summary and conclusion . . . 119
Chapter 5: Probing protoplanetary disk gas surface density distribution with 13CO emission 123 5.1 Introduction . . . 125
5.2 Modeling . . . 127
5.2.1 DALI . . . 127
5.2.2 Grid of models . . . 127
5.3 Results . . . 131
5.3.1 Simple power-law . . . 131
5.3.2 Self-similar disk models . . . 135
5.3.3 Inner disk surface density profile from C17O line intensity ra- dial profiles . . . 136
5.3.4 The “slope-pivot-region” . . . 137
5.4 Discussion . . . 139
5.5 Summary and conclusion . . . 140
Appendices 5.A Additional figures . . . 143
Chapter 6: HD far infrared emission as a measure of protoplanetary disk mass147 6.1 Introduction . . . 149
6.2 Model . . . 151
6.2.1 Density structure . . . 152
6.2.2 Dust settling . . . 152
6.2.3 Chemical network . . . 153
6.2.4 Grid of models . . . 154
6.3 Results . . . 156
6.3.1 HD flux vs. disk gas mass . . . 156
6.3.2 HD emitting layers . . . 157
6.3.3 Influence of the vertical structure . . . 159
6.3.4 Influence of the large grains . . . 160
6.3.5 Influence of the gas-to-dust ratio . . . 161
6.3.6 Line-to-Continuum ratios . . . 164
6.3.7 Sensitivities of future FIR missions . . . 166
6.4 Discussion . . . 167
6.4.1 Determining the disk gas mass . . . 167
6.4.2 HD 1-0 and HD 2-1 line fluxes . . . 169
6.4.3 Comparing models to observations . . . 170
6.4.4 Case study: TW Hya . . . 171
6.5 Conclusions . . . 174
Appendices 6.A Abundance and temperature maps of TW Hya . . . 176
6.B Abundance and emission maps of grid models . . . 179
6.C Effects of including hydrostatic equilibrium . . . 181
6.C.1 The hydrostatic solver . . . 181
6.C.2 Comparing with parametrized vertical structure . . . 182
6.D Deuterium chemistry . . . 183
6.E Line fluxes of the TW Hya model . . . 184
