Filling in the Gaps: Illuminating (a) Clearing Mechanisms in Transitional Protoplanetary Disks, and (b) Quantitative Illiteracy among Undergraduate Science Students

2.50
Hdl Handle:
http://hdl.handle.net/11290/608080
Title:
Filling in the Gaps: Illuminating (a) Clearing Mechanisms in Transitional Protoplanetary Disks, and (b) Quantitative Illiteracy among Undergraduate Science Students
Authors:
Follette, Katherine Brutlag
Abstract:
What processes are responsible for the dispersal of protoplanetary disks? In this dissertation, beginning with a brief Introduction to planet detection, disk dispersal and high-contrast imaging in Chapter 1, I will describe how ground-based adaptive optics (AO) imaging can help to inform these processes. Chapter 2 presents Polarized Differential Imaging (PDI) of the transitional disk SR21 at H-band taken as part of the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS). These observations were the first to show that transition disk cavities can appear markedly different at different wavelengths. The observation that the sub-mm cavity is absent in NIR scattered light is consistent with grain filtration at a planet-induced gap edge. Chapter 3 presents SEEDS data of the transition disk Oph IRS 48. This highly asymmetrical disk is also most consistent with a planet-induced clearing mechanism. In particular, the images reveal both the disk cavity and a spiral arm/divot that had not been imaged previously. This study demonstrates the power of multiwavelength PDI imaging to verify disk structure and to probe azimuthal variation in grain properties. Chapter 4 presents Magellan visible light adaptive optics imaging of the silhouette disk Orion 218-354. In addition to its technical merits, these observations reveal the surprising fact that this very young disk is optically thin at H-alpha. The simplest explanation for this observation is that significant grain growth has occurred in this disk, which may be responsible for the pre-transitional nature of its SED. Chapter 5 presents brief descriptions of several other works-in-progress that build on my previous work. These include the MagAO Giant Accreting Protoplanet Survey (GAPlanetS), which will probe the inner regions of transition disks at unprecedented resolution in search of young planets in the process of formation. Chapters 6-8 represent my educational research in quantitative literacy, beginning with an introduction to the literature and study motivation in Chapter 6. Chapter 7 describes the development and validation of the Quantitative Reasoning for College Science (QuaRCS) Assessment instrument. Chapter 8 briefly describes the next steps for Phase II of the QuaRCS study.
Affiliation:
University of Arizona
Issue Date:
2014
URI:
http://hdl.handle.net/11290/608080
Submitted date:
2016-02-25
Document Source:
Dissertation/Thesis
Language:
English Paper
Type Of Resource:
Empirical Research
Empirical Methodology:
Quantitative
Learning Environment:
Formal
Subjects:
College Students
Construct:
Quantitative Reasoning
Nation:
USA
Appears in Collections:
Astronomy Education Research

Full metadata record

DC FieldValue Language
dc.contributor.authorFollette, Katherine Brutlagen
dc.date.accessioned2016-05-04T09:01:34Zen
dc.date.available2016-05-04T09:01:34Zen
dc.date.issued2014en
dc.date.submitted2016-02-25en
dc.identifier.urihttp://hdl.handle.net/11290/608080en
dc.description.abstractWhat processes are responsible for the dispersal of protoplanetary disks? In this dissertation, beginning with a brief Introduction to planet detection, disk dispersal and high-contrast imaging in Chapter 1, I will describe how ground-based adaptive optics (AO) imaging can help to inform these processes. Chapter 2 presents Polarized Differential Imaging (PDI) of the transitional disk SR21 at H-band taken as part of the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS). These observations were the first to show that transition disk cavities can appear markedly different at different wavelengths. The observation that the sub-mm cavity is absent in NIR scattered light is consistent with grain filtration at a planet-induced gap edge. Chapter 3 presents SEEDS data of the transition disk Oph IRS 48. This highly asymmetrical disk is also most consistent with a planet-induced clearing mechanism. In particular, the images reveal both the disk cavity and a spiral arm/divot that had not been imaged previously. This study demonstrates the power of multiwavelength PDI imaging to verify disk structure and to probe azimuthal variation in grain properties. Chapter 4 presents Magellan visible light adaptive optics imaging of the silhouette disk Orion 218-354. In addition to its technical merits, these observations reveal the surprising fact that this very young disk is optically thin at H-alpha. The simplest explanation for this observation is that significant grain growth has occurred in this disk, which may be responsible for the pre-transitional nature of its SED. Chapter 5 presents brief descriptions of several other works-in-progress that build on my previous work. These include the MagAO Giant Accreting Protoplanet Survey (GAPlanetS), which will probe the inner regions of transition disks at unprecedented resolution in search of young planets in the process of formation. Chapters 6-8 represent my educational research in quantitative literacy, beginning with an introduction to the literature and study motivation in Chapter 6. Chapter 7 describes the development and validation of the Quantitative Reasoning for College Science (QuaRCS) Assessment instrument. Chapter 8 briefly describes the next steps for Phase II of the QuaRCS study.en
dc.description.provenanceMade available in DSpace on 2016-05-04T09:01:34Z (GMT). No. of bitstreams: 1 9fe5441a-8969-45b2-bb96-b8567451c015.pdf: 9409027 bytes, checksum: 8558133a2966cf2c532082eb2d32e2b3 (MD5) Previous issue date: 2014en
dc.language.isoEnglish Paperen
dc.titleFilling in the Gaps: Illuminating (a) Clearing Mechanisms in Transitional Protoplanetary Disks, and (b) Quantitative Illiteracy among Undergraduate Science Studentsen
dc.typeDissertation/Thesisen
dc.contributor.departmentUniversity of Arizonaen
dc.type.resourceEmpirical Researchen
dc.istar.learningenvironmentFormalen
dc.istar.constructQuantitative Reasoningen
dc.istar.nationUSAen
dc.istar.empiricalmethodologyQuantitativeen
dc.istar.subjectCollege Studentsen
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