Describing protostellar disk structure in Ophiuchus

Young forming stars host circumstellar disks of dust and gas. High-resolution, millimeter observations of disks at the protoplanetary stage reveal substructures such as gaps, rings, arcs, spirals, and cavities. These structures are often attributed to disturbances from young, newly formed planets or mechanisms conducive to planet formation. However, the formation mechanisms of the substructures are unconstrained, and only a few disks at the younger protostellar stage have known substructures to date. In this thesis, we present a detailed analysis of 1.3 and 0.87 mm observations of ten protostellar disks in the Ophiuchus star-forming region in a search for the origins of the substructure. Of the sample of ten, four disks have identified structure, three are smooth disks, and three are ambiguous. The structured disks have wide Gaussian-like rings (σR/Rdisk ∼ 0.26) above a smooth disk profile with low contrasts (C < 0.2) in comparison to protoplanetary disks where the rings are narrow and have a wide variety of contrasts (σR/Rdisk ∼ 0.08 and C ranges from 0 − 1). These structured protostellar disks are the brightest sources in the Ophiuchus sample, in agreement with trends observed for protoplanetary disks, and two show evidence of flaring, indicating large dust grains have not had time to fully settle onto the midplane of the disk. These observations indicate that structure in protostellar disks may be common. The presence of structure at the earliest stages suggests an early start for dust grain growth and, subsequently planet formation.

Department dc:contributor.department

Physics, Engineering Physics and Astronomy

Author dc:creator

• Michel, Arnaud

Advisor dc:contributor.supervisor

• Sadavoy, Sarah I.

• Astronomy
• Physics
• Protostellar disks

Statement dc:rights

• Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
• ProQuest PhD and Master's Theses International Dissemination Agreement
• Intellectual Property Guidelines at Queen's University
• Copying and Preserving Your Thesis
• This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
• Attribution-NonCommercial-NoDerivs 3.0 United States

Licence dc:rights.uri

• http://creativecommons.org/licenses/by-nc-nd/3.0/us/

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1974/30488

OAI identifier oai:identifier

oai:queensu.scholaris.ca:1974/30488