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.
{ "@context": "https://schema.org/", "@id": 45141, "@type": "ScholarlyArticle", "creator": [ { "@type": "Person", "name": "McGraw, S. M." }, { "@type": "Person", "name": "Brandt, W. N." }, { "@type": "Person", "name": "Grier, C. J." }, { "@type": "Person", "name": "Ak, N. Filiz" }, { "@type": "Person", "affiliation": "York Univ, Dept Phys & Astron, 4700 Keele St, Toronto, ON M3J 1P3, Canada", "name": "Hall, P. B." }, { "@type": "Person", "name": "Schneider, D. P." }, { "@type": "Person", "affiliation": "Univ Washington, Dept Astron, Box 351580, Seattle, WA 98195 USA", "name": "Anderson, S. F." }, { "@type": "Person", "affiliation": "Harvard Smithsonian Ctr Astrophys, 60 Garden Sreet, Cambridge, MA 02138 USA", "name": "Green, P. J." }, { "@type": "Person", "affiliation": "Univ Utah, Dept Phys & Astron, 115 S 1400 E, Salt Lake City, UT 84112 USA", "name": "Hutchinson, T. A." }, { "@type": "Person", "affiliation": "Harvard Smithsonian Ctr Astrophys, 60 Garden Sreet, Cambridge, MA 02138 USA", "name": "Macleod, C. L." }, { "@type": "Person", "affiliation": "Univ Utah, Dept Phys & Astron, 115 S 1400 E, Salt Lake City, UT 84112 USA", "name": "Vivek, M." } ], "datePublished": "2017-01-01", "description": "We investigate broad absorption line (BAL) disappearance and emergence using a 470 BAL-quasar sample over <= 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 <= 1.73-4.62 rest-frame years and 18 emerging BALs over <= 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 <= 3.88 rest-frame years on average and three re-disappearing BALs over <= 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.", "headline": "Broad absorption line disappearance and emergence using multiple-epoch spectroscopy from the Sloan Digital Sky Survey", "identifier": 45141, "image": "https://aperta.ulakbim.gov.tr/static/img/logo/aperta_logo_with_icon.svg", "license": "http://www.opendefinition.org/licenses/cc-by", "name": "Broad absorption line disappearance and emergence using multiple-epoch spectroscopy from the Sloan Digital Sky Survey", "url": "https://aperta.ulakbim.gov.tr/record/45141" }
Görüntülenme | 35 |
İndirme | 7 |
Veri hacmi | 2.3 kB |
Tekil görüntülenme | 34 |
Tekil indirme | 7 |