Publication Date

2014

Document Type

Honors Thesis

Department

Physics

Keywords

Stars-Formation, Accretion (Astrophysics), Stellar winds, Astronomical spectroscopy, Star formation, Accretion disk, Line profiles

Abstract

T Tauri stars are young low mass stars surrounded by accretion disks that are in the process of forming planets. In addition to stellar photospheres these stars show a lot of spectral activity deriving from accretion through the disk onto the star via magnetic "funnels", from accretion shocks on the stellar surface, accretion powered winds and the disk itself. All of these phenomena occur in the region where the star and the disk interact with each other, but our knowledge of the region is not very complete. In order to better understand these processes we need to separate out their individual contributions from the complex emission activity. Emission lines in T Tauri stars often have complex kinematic features that suggest a composite origin. I have begun a line profile analysis for 17 T Tauri stars based on simultaneous optical and near infrared spectra taken with the Keck telescopes on Mauna Kea. My goal is to identify kinematic components in different lines and compare them to each other, to disk inclinations, to accretion rates and to local line excitation models of Kwan and Fischer (2011). To date, I have decomposed lines of the Paschen series, Ca II infrared triplet, He I 5876 and OI 8446 into multiple Gaussian components. I identify commonalities among these three lines and use ratios of similar kinematic components to explore physical conditions in the line-forming region.

Language

English

Comments

78 pages : color illustrations. Honors Project-Smith College, 2014. Includes bibliographical references (pages 77-78)

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