• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    STAR FORMATION IN THE RHO OPHIUCHI DARK CLOUD

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_8200323_sip1_w.pdf
    Size:
    5.401Mb
    Format:
    PDF
    Download
    Author
    Wilking, Bruce Alan
    Issue Date
    1981
    Keywords
    Stars -- Evolution.
    Infrared astronomy.
    Millimeter wave devices.
    Advisor
    Rieke, George
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    New and sensitive millimeter-wave and near-infrared observation have been performed in the central regions of the ρ Ophiuchi dark cloud. High spatial resolution observations of the optically thin C¹⁸O emission lines are shown to be free of self-absorption. They permit the first accurate determination of the distribution of molecular gas and allow us to estimate the mass and visual extinction in the cloud. A completely sampled near-infrared survey of a 105 sq. arcmin area which encloses the region of highest visual extinction has revealed twenty objects (sixteen were previously unknown). We show that these objects are young stars embedded in the cloud. Synthesizing our new observations with existing radio and infrared data, we have made a detailed study of the energetics and star formation process within the ρ Oph cloud. This dissertation concludes that the high temperatures of the molecular gas cannot be due to collisions with warm dust. The feasibility of alternate heat sources such as cosmic-ray ionization, shocks, and the distortion of magnetic fields are discussed. We derive high star formation efficiencies (32-46%) in the centrally condensed core of the ρ Oph cloud which suggests that it is forming a bound open cluster. The most consistent interpretation of our data requires that an efficient burst of star formation has produced a relatively large (with respect to the initial mass function) population of low luminosity stars in ρ Oph within the last 3 million years. At this present rate of star formation, most of the molecular gas will be converted into stars in about 10⁷ yr. yielding a bound cluster. Unless this rate rapidly decreases with time, the duration of star formation in the (rho) Oph cluster (10 million years) will be considerably shorter than that suggested for the Pleiades cluster (175 m. y). The lack of stars in the 3-10 M(⊙) range indicates that subsequent star formation must be dominated by more massive stars if the stellar mass spectrum of the ρ Oph cluster is to resemble that of the conventional initial mass function. The youth of the ρ Oph cluster suggests that it may be the most recent episode of star formation in the Sco-Cen OB association.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Planetary Sciences
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.