• 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

    Black Hole Growth and Star Formation in a Complete Sample of Seyfert Galaxies

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_etd_11264_sip1_m.pdf
    Size:
    1.956Mb
    Format:
    PDF
    Download
    Author
    Diamond-Stanic, Aleksandar
    Issue Date
    2010
    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
    I investigate methods for determining black hole accretion rates and star-formation rates in galaxies hosting active galactic nuclei (AGNs) and use these results to identify biases in our census of black hole growth, to probe fundamental differences between obscured and unobscured AGNs, and to explore the connection between black hole growth and galaxy evolution. I show that the mid-infrared [O IV] emission line, which probes high-ionization gas and suffers little dust attenuation, is a useful diagnostic of AGN luminosity. Using [O IV] measurements for a complete sample of Seyfert galaxies, I show that the intrinsic luminosities of obscured and unobscured AGNs are quite similar. This is in contrast to the [O III] optical emission line and hard X-ray continuum luminosities, which are systematically smaller for obscured Seyferts, revealing strong biases in existing AGN surveys. I also explore the effect of AGNs on the mid-infrared aromatic features, which are useful probes of star-formation activity. I find that the 6.2, 7.7, and 8.6 micron features are suppressed relative to the 11.3 micron feature in Seyfert galaxies, and show that this behavior is correlated with the strength of the rotational H2 (molecular hydrogen) emission, which traces shocked gas. This suggests that shocks associated with the AGN modify the structure of aromatic molecules, but I show that the 11.3 micron aromatic feature is robust to the effects of such shock processing, and use it to estimate nuclear star-formation rates for AGN host galaxies. I find an approximately linear relationship between black hole accretion rate and nuclear star-formation rate, and show that high-luminosity AGNs reside in galaxies with more centrally concentrated star formation. This suggests that the strength of AGN activity is driven by the amount of gas in the central few hundred parsecs, and is consistent with models where AGN activity is linked with elevated nuclear star formation.
    Type
    Electronic Dissertation
    text
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Graduate College
    Astronomy
    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.