Cover Page
The following handle holds various files of this Leiden University dissertation:
http://hdl.handle.net/1887/80839
Author: Haffert, S.Y.
High-resolution integral-field spectroscopy
of exoplanets
Proefschrift
ter verkrijging van
de graad van Doctor aan de Universiteit Leiden, op gezag van Rector Magnificus prof. mr. C.J.J.M. Stolker,
volgens besluit van het College voor Promoties te verdedigen op dinsdag 26 November 2019
klokke 11.15 uur
door
Sebastiaan Yannick Haffert
geboren te Zoetemeer, Nederland
Promotor: Prof. dr. Christoph Keller Co-promotor: Prof. dr. Ignas Snellen
Promotiecommissie: Prof. dr. Huub R¨ottgering Universiteit Leiden Prof. dr. Bernard Brandl Universiteit Leiden Prof. dr. Ewine van Dishoeck Universiteit Leiden
Prof. dr. Paul Urbach Technische Universiteit Delft Prof. dr. Roland Bacon Universit´e de Lyon
Prof. dr. Anne-Marie Lagrange Universit´e Grenoble Alpes Dr. Laura Kreidberg Harvard University
Cover design: An artist’s impression of the two accreting proto-planets around PDS 70 made by J. Olmsted (NASA/STScI). Text design by E. Timmerman (Op-tima).
ISBN: 978-94-6361-342-2
An electronic copy of this thesis can be found at https://openaccess.leidenuniv.nl c
iv
Contents
1 Introduction 1
1.1 The direct imaging challenge . . . 5
1.1.1 The Earth atmosphere . . . 5
1.1.2 Adaptive optics . . . 6
1.1.3 High-contrast imaging . . . 9
1.1.4 Post-processing . . . 11
1.1.5 The powers of ten in exoplanet spectroscopy . . . . 13
1.2 Thesis outline . . . 16
1.3 Outlook . . . 17
2 The Leiden Exoplanet Instrument 23 2.1 Introduction . . . 24
2.2 Prototype optical design . . . 25
2.2.1 LEXI Adaptive optics system . . . 25
2.2.2 Non-common path correction and coronagraph . . . 28
2.2.3 High-resolution spectrograph . . . 30
2.3 First light . . . 31
2.4 Conclusion and outlook . . . 34
3 On-sky results of the Leiden EXoplanet Instrument(LEXI) 37 3.1 Introduction . . . 38
3.2 LEXI overview . . . 39
3.3 The adaptive optics module of LEXI . . . 41
3.4 Focal-plane wavefront sensing with the cMWS . . . 44
3.5 Single-mode fiber-fed spectroscopy . . . 47
3.6 Conclusion and outlook . . . 51
4 The Single-mode Complex Amplitude Refinement corona-graph I. 55 4.1 Introduction . . . 56
4.2 Modal filtering using single-mode fibers . . . 59
4.2.1 Nulling in single-mode fibers . . . 59
4.2.2 Single-mode fiber arrays using microlenses . . . 60
4.3 Coronagraphy with a single-mode fiber array . . . 64
4.3.1 Conventional coronagraphy . . . 64
4.3.2 Direct pupil-plane phase mask optimization . . . 67
4.4 Single-mode fiber coronagraph properties . . . 73
4.4.1 Fiber mode field diameter . . . 73
CONTENTS vi
4.4.3 Spectral bandwidth . . . 78
4.4.4 Tip-tilt sensitivity and stellar diameter . . . 78
4.4.5 Sensitivity to other aberrations . . . 79
4.5 Comparison to the vortex coronagraph . . . 80
4.6 Conclusion . . . 86
5 The Single-mode Complex Amplitude Refinement corona-graph II. 89 5.1 Introduction . . . 90
5.2 Optical setup details and first results . . . 92
5.2.1 Lab setup description . . . 92
5.2.2 Fiber alignment procedure . . . 94
5.2.3 Apodizing phase plate designs . . . 94
5.2.4 Liquid crystal plate . . . 96
5.2.5 Lab setup results . . . 96
5.3 Tolerance simulation analysis . . . 104
5.3.1 Fiber alignment tolerance . . . 105
5.3.2 MLA surface . . . 106
5.3.3 Fiber mode shape . . . 107
5.3.4 FIU Monte Carlo analysis . . . 108
5.4 Conclusions . . . 110
6 Two accreting protoplanets around the young star PDS 70113 6.1 Content . . . 114
6.2 Methods . . . 121
6.2.1 VLT/MUSE observations and data reduction. . . 121
6.2.2 High-resolution spectral differential imaging (HRSDI). 122 6.2.3 Aperture photometry of both companions and SNR determination. . . 123
6.2.4 Astrometry of the Hα emission from PDS 70 b and c. 123 6.2.5 Orbit radius and mean motion resonance estimation. 126 6.2.6 SPHERE and NACO archival data reduction. . . 129
6.2.7 Astrometry and photometry extraction of PDS 70 b and c from NACO and SPHERE data. . . 130
6.2.8 Mass determination of PDS 70 c. . . 131
7 Multiplexed gratings for gas sensing in planetary atmo-spheres 135 7.1 Introduction . . . 136
vii CONTENTS
7.2.1 Bragg grating basics . . . 139
7.2.2 Multiplexed Bragg gratings . . . 141
7.2.3 Simulating diffraction efficiencies . . . 144
7.3 Advantages of multiplexed Bragg gratings . . . 145
7.4 Multiplexed Bragg grating implementation . . . 147
7.4.1 Static system . . . 147
7.4.2 Dynamic system . . . 148
7.4.3 Challenges when implementing as a hyper-spectral imager . . . 149
7.5 Applications of the Highly Multiplexed Bragg Grating . . . 151
7.5.1 Highly Multiplexed Bragg Grating instrument model 151 7.5.2 Abundance retrieval of molecular species . . . 152
7.5.3 Molecule maps . . . 154
7.5.4 Exoplanet detection . . . 156
7.6 Conclusion . . . 158
8 English Summary 161
