1 Ocak 2017 Dergi makalesi Açık Erişim

McGraw, S. M.; Brandt, W. N.; Grier, C. J.; Ak, N. Filiz; Hall, P. B.; Schneider, D. P.; Anderson, S. F.; Green, P. J.; Hutchinson, T. A.; Macleod, C. L.; Vivek, M.

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  <identifier identifierType="URL">https://aperta.ulakbim.gov.tr/record/45141</identifier>
  <creators>
    <creator>
      <creatorName>McGraw, S. M.</creatorName>
      <givenName>S. M.</givenName>
      <familyName>McGraw</familyName>
    </creator>
    <creator>
      <creatorName>Brandt, W. N.</creatorName>
      <givenName>W. N.</givenName>
      <familyName>Brandt</familyName>
    </creator>
    <creator>
      <creatorName>Grier, C. J.</creatorName>
      <givenName>C. J.</givenName>
      <familyName>Grier</familyName>
    </creator>
    <creator>
      <creatorName>Ak, N. Filiz</creatorName>
      <givenName>N. Filiz</givenName>
      <familyName>Ak</familyName>
    </creator>
    <creator>
      <creatorName>Hall, P. B.</creatorName>
      <givenName>P. B.</givenName>
      <familyName>Hall</familyName>
      <affiliation>York Univ, Dept Phys &amp; Astron, 4700 Keele St, Toronto, ON M3J 1P3, Canada</affiliation>
    </creator>
    <creator>
      <creatorName>Schneider, D. P.</creatorName>
      <givenName>D. P.</givenName>
      <familyName>Schneider</familyName>
    </creator>
    <creator>
      <creatorName>Anderson, S. F.</creatorName>
      <givenName>S. F.</givenName>
      <familyName>Anderson</familyName>
      <affiliation>Univ Washington, Dept Astron, Box 351580, Seattle, WA 98195 USA</affiliation>
    </creator>
    <creator>
      <creatorName>Green, P. J.</creatorName>
      <givenName>P. J.</givenName>
      <familyName>Green</familyName>
      <affiliation>Harvard Smithsonian Ctr Astrophys, 60 Garden Sreet, Cambridge, MA 02138 USA</affiliation>
    </creator>
    <creator>
      <creatorName>Hutchinson, T. A.</creatorName>
      <givenName>T. A.</givenName>
      <familyName>Hutchinson</familyName>
      <affiliation>Univ Utah, Dept Phys &amp; Astron, 115 S 1400 E, Salt Lake City, UT 84112 USA</affiliation>
    </creator>
    <creator>
      <creatorName>Macleod, C. L.</creatorName>
      <givenName>C. L.</givenName>
      <familyName>Macleod</familyName>
      <affiliation>Harvard Smithsonian Ctr Astrophys, 60 Garden Sreet, Cambridge, MA 02138 USA</affiliation>
    </creator>
    <creator>
      <creatorName>Vivek, M.</creatorName>
      <givenName>M.</givenName>
      <familyName>Vivek</familyName>
      <affiliation>Univ Utah, Dept Phys &amp; Astron, 115 S 1400 E, Salt Lake City, UT 84112 USA</affiliation>
    </creator>
  </creators>
  <titles>
    <title>Broad Absorption Line Disappearance And Emergence Using Multiple-Epoch Spectroscopy From The Sloan Digital Sky Survey</title>
  </titles>
  <publisher>Aperta</publisher>
  <publicationYear>2017</publicationYear>
  <dates>
    <date dateType="Issued">2017-01-01</date>
  </dates>
  <resourceType resourceTypeGeneral="Text">Journal article</resourceType>
  <alternateIdentifiers>
    <alternateIdentifier alternateIdentifierType="url">https://aperta.ulakbim.gov.tr/record/45141</alternateIdentifier>
  </alternateIdentifiers>
  <relatedIdentifiers>
    <relatedIdentifier relatedIdentifierType="DOI" relationType="IsIdenticalTo">10.1093/mnras/stx1063</relatedIdentifier>
  </relatedIdentifiers>
  <rightsList>
    <rights rightsURI="http://www.opendefinition.org/licenses/cc-by">Creative Commons Attribution</rights>
    <rights rightsURI="info:eu-repo/semantics/openAccess">Open Access</rights>
  </rightsList>
  <descriptions>
    <description descriptionType="Abstract">We investigate broad absorption line (BAL) disappearance and emergence using a 470 BAL-quasar sample over &amp;lt;= 0.10-5.25 rest-frame years with at least three spectroscopic epochs for each quasar from the Sloan Digital Sky Survey. We identify 14 disappearing BALs over &amp;lt;= 1.73-4.62 rest-frame years and 18 emerging BALs over &amp;lt;= 1.46-3.66 rest-frame years associated with the C IV lambda 1548,1550 and/or Si IV lambda lambda 1393,1402 doublets, and report on their variability behaviour. BAL quasars in our data set exhibit disappearing/emerging C IV BALs at a rate of 2.3(-0.7)(+0.9) and 3.0(-0.8)(+1.0) per cent, respectively, and the frequency for BAL to non-BAL quasar transitions is 1.7(-0.6)(+0.8) per cent. We detect four re-emerging BALs over &amp;lt;= 3.88 rest-frame years on average and three re-disappearing BALs over &amp;lt;= 4.15 rest-frame years on average, the first reported cases of these types. We infer BAL lifetimes along the line of sight to be nominally less than or similar to 100-1000 yr using disappearing C IV BALs in our sample. Interpretations of (re-) emerging and (re-) disappearing BALs reveal evidence that collectively supports both transverse-motion and ionization-change scenarios to explain BAL variations. We constrain a nominal C IV/Si IV BAL-outflow location of less than or similar to 100 pc from the central source and a radial size of greater than or similar to 1x 10(-7) pc (0.02 au) using the ionization-change scenario, and constrain a nominal outflow location of less than or similar to 0.5 pc and a transverse size of similar to 0.01 pc using the transverse-motion scenario. Our findings are consistent with previous work, and provide evidence in support of BALs tracing compact flow geometries with small filling factors.</description>
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