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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.
<?xml version='1.0' encoding='utf-8'?> <resource xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://datacite.org/schema/kernel-4" xsi:schemaLocation="http://datacite.org/schema/kernel-4 http://schema.datacite.org/meta/kernel-4.1/metadata.xsd"> <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 & 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 & 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 & 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 &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 &lt;= 1.73-4.62 rest-frame years and 18 emerging BALs over &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 &lt;= 3.88 rest-frame years on average and three re-disappearing BALs over &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> </descriptions> </resource>
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