• 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

    An optical-infrared study of radio-loud quasar environments

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_9817363_sip1_m.pdf
    Size:
    6.721Mb
    Format:
    PDF
    Download
    Author
    Hall, Patrick Brian, 1968-
    Issue Date
    1998
    Keywords
    Physics, Astronomy and Astrophysics.
    Advisor
    Green, Richard F.
    
    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 present the data for an optical/near-infrared study of radio-loud quasar environments from z = 0.6-2.0, and the analysis of the data from z = 1.0-2.0. I thoroughly discuss the sample selection, observing, data reduction, and object cataloging. Even accounting for possible systematic offsets, I find a significant excess of K ≳ 19 galaxies in the fields of z = 1-2 RLQs, on two spatial scales. One component is at θ <40'' from the quasars and is significant compared to the galaxy surface density at θ >40'' in the same fields. The other component appears roughly uniform across the fields (to θ∼100'') and is significant compared to the galaxy surface density seen in random-field surveys in the literature. The r-K color distributions of the excess galaxy populations are indistinguishable, and are significantly redder than the color distribution of the field population. The excess galaxy population is thus consistent with being predominantly early-type galaxies at the quasar redshifts. The average excess within 0.5h⁻¹₇₅ Mpc $(∼65'') of the quasars corresponds to Abell richness class ∼0 compared to the galaxy surface density at >0.5h⁻¹₇₅ Mpc from the quasars, and to Abell richness class ∼1 compared to that from the literature. I estimate -0.65⁺⁰·⁴¹₋₀.₅₅ magnitudes of evolution in M*(K) to z̄ = 1.67 by assuming the excess galaxies are at the quasar redshifts. I discuss the spectral energy distributions (SEDs) of galaxies in fields with data in several passbands. Most candidate quasar-associated galaxies are consistent with being 2-3 Gyr old early-types at the quasar redshifts of z∼1.5. However, some objects have SEDs similar to extremely late-type stars; others have SEDs consistent with being 4-5 Gyr old at z∼1.5 and others are consistent with old but dust-reddened galaxies at the quasar redshifts. These potentially different galaxy types suggest there may be considerable dispersion in the properties of early-type cluster galaxies at z∼1.5. There is also a population of galaxies whose SEDs are best modelled by background galaxies at z≳2.5, Many of these are dusty or have composite stellar populations, or both, and some may be ≳2 Gyr old at z≳ 2.5. Confirmation of old galaxies at high redshift would constrain the cosmology by requiring a relatively old universe at large lookback times.
    Type
    text
    Dissertation-Reproduction (electronic)
    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.