High-Angular Resolution Mid-Infrared Study of Disks and Environments of Young Stars

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Material Information

Title:
High-Angular Resolution Mid-Infrared Study of Disks and Environments of Young Stars
Physical Description:
1 online resource (181 p.)
Language:
english
Creator:
Li, Dan
Publisher:
University of Florida
Place of Publication:
Gainesville, Fla.
Publication Date:

Thesis/Dissertation Information

Degree:
Doctorate ( Ph.D.)
Degree Grantor:
University of Florida
Degree Disciplines:
Astronomy
Committee Chair:
TELESCO,CHARLES MICHAEL
Committee Co-Chair:
FORD,ERIC
Committee Members:
TAN,JONATHAN CHARLES
FRY,JAMES N
PANTIN,ERIC

Subjects

Subjects / Keywords:
astronomy -- astrophysics -- herbig -- observation -- stars -- yso
Astronomy -- Dissertations, Academic -- UF
Genre:
Astronomy thesis, Ph.D.
bibliography   ( marcgt )
theses   ( marcgt )
government publication (state, provincial, terriorial, dependent)   ( marcgt )
born-digital   ( sobekcm )
Electronic Thesis or Dissertation

Notes

Abstract:
Recent advances in astronomical instrumentation have allowed us to explore the environments of young stars in unprecedented detail. In particular, mid-infrared cameras on large ground-based telescopes have been used extensively to study the properties of protoplanetary disks through their thermal emissions originating in the dust. With 8-to-10 m class telescopes, observations in the mid-IR (8-25 micron) band can achieve a sub-arcsec resolution and a decent field of view that are ideal for probing disk structures on scales from sub-AU to tens-of-AU. Such observations have been used, for example, to confirm the two types of protoplanetary disk, flared and self-shadowed, and a probable evolutionary connection between them. In addition to the classic mid-IR imaging and spectroscopy, dual-beam imaging polarimetry has been introduced by CanariCam at the 10.4 m Grand Telescopio Canarias (GTC). It is expected that the mid-IR polarized light will provide us, for the first time, with direct clues about morphologies of the magnetic fields in protoplanetary disks. The work presented by this dissertation is an observational study of the environments, including disks, around young stars, making use of mid-IR images and spectra obtained with 8-to-10 m telescopes. Based on the camera performance and data characteristics that we learned from our experience with major mid-IR instruments (e.g., T-ReCS, Michelle, and CanariCam), I developed an Interactive Data Language (IDL) package of routines optimized for reducing the data and correcting for image defects commonly seen in ground-based mid-IR data.  I obtained, reduced, and analyzed mid-IR images and spectra of the debris disk Beta Pic. It is found that multiple dust populations co-exist in the disk. Their spatial distributions could be a signature of an asteroid belt, or alternatively, a consequence of stellar heating. Using the dual-epoch imaging data, I confirmed the existence of a dusty clump in the disk wing, and also found its movement, the amount of which is consistent with a Keplerian motion over 7 years. I observed MWC 1080, a Herbig Ae/Be star in a small, young cluster. Our high resolution images suggest that the complex structure around MWC 1080, observed in both mid-IR and other bands, can be explained by a bipolar cavity cleared by the outflow from MWC 1080. Through a pilot program, I observed several Herbig Ae/Be stars with various modes, including the imaging spectroscopy, of CanariCam. I used the data to demonstrate CanariCam's on-sky performance, and to improve the current observation strategies and data reduction routines.
General Note:
In the series University of Florida Digital Collections.
General Note:
Includes vita.
Bibliography:
Includes bibliographical references.
Source of Description:
Description based on online resource; title from PDF title page.
Source of Description:
This bibliographic record is available under the Creative Commons CC0 public domain dedication. The University of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
Statement of Responsibility:
by Dan Li.
Thesis:
Thesis (Ph.D.)--University of Florida, 2013.
Local:
Adviser: TELESCO,CHARLES MICHAEL.
Local:
Co-adviser: FORD,ERIC.
Electronic Access:
RESTRICTED TO UF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE UNTIL 2014-12-31

Record Information

Source Institution:
UFRGP
Rights Management:
Applicable rights reserved.
Classification:
lcc - LD1780 2013
System ID:
UFE0046185:00001