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Description
Title: | Understanding the star-forming environment in stellar clusters |
Author(s): | Wang, Shiya |
Director of Research: | Looney, Leslie W. |
Doctoral Committee Member(s): | Chu, You-Hua; Crutcher, Richard M.; Fields, Brian |
Department / Program: | Astronomy |
Discipline: | Astronomy |
Degree Granting Institution: | University of Illinois at Urbana-Champaign |
Degree: | Ph.D. (doctoral) |
Genre: | Dissertation |
Subject(s): | Star-forming environment
Stellar clusters Low-mass cluster members |
Abstract: | The main goal of this thesis is to investigate the physical conditions of the star-forming environment in stellar clusters, especially for the formation of low-mass cluster members. Embedded, young, and intermediate-mass stellar clusters around Herbig . Ae/Be stars are sampled. Mid- and near-infrared observations identifying young stars and millimeter interferometric observations probing dense molecular gas and dust continuum are presented. These observations are used to reveal the large-scale young stellar population around the vicinity where the sampled clusters form, probe the physical conditions of dense molecular clumps which are capable of forming individual low-mass cluster members, and examine the influence of the most massive star in the cluster on its siblings and natal cluster-forming cloud. This study shows that stars within the cluster tend to seem younger than those outside the cluster, suggesting a higher and continuous star-forming rate within the cluster than outside, or massive stars are initiated later than low-mass star within the same cloud. A thorough investigation of young stars and dense gas toward the MWC·l080 cluster further suggests a domination of the.most massive star in the cluster on both the natal cloud dispersal and its low-mass cluster members. As active outflows and winds from the Herbig Ae/Be stars increase the non-thermal motion in the cloud, low-mass cluster members are formed within denser and more. turbulent cores, than isolated low-mass star-forming cores. In addition, the strong gas dispersal from the Herbig Ae/Be stars also helps the removal of the circumstellar material around nearby low-mass stars. This makes these low-mass cluster members appear older. In summary, this thesis provides the observational evidence showing how the most massive star in the cluster affects the formation and evolution of low-mass cluster members and the physical conditions of star formation in the cluster. |
Issue Date: | 2008 |
Publisher: | Department of Astronomy. College of Liberal Arts and Science. The University of Illinois at Urbana-Champaign. |
Genre: | Dissertation / Thesis |
Type: | Text |
Language: | English |
URI: | http://hdl.handle.net/2142/79033 |
Date Available in IDEALS: | 2015-08-11 |