Item type |
学術雑誌論文 / Journal Article(1) |
公開日 |
2013-12-02 |
タイトル |
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タイトル |
C IV and other metal absorption line systems in 18 z=4 quasars |
言語 |
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言語 |
eng |
DOI |
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関連識別子 |
https://doi.org/10.1086/339313 |
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関連名称 |
10.1086/339313 |
キーワード |
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主題 |
galaxies : abundances, galaxies : evolution, quasars : absorption lines |
資源タイプ |
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資源 |
http://purl.org/coar/resource_type/c_6501 |
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タイプ |
journal article |
著者 |
Misawa, T
Tytler, D
Iye, M
Storrie-Lombardi, LJ
Suzuki, N
Wolfe, AM
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信州大学研究者総覧へのリンク |
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氏名 |
Misawa, T |
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URL |
http://soar-rd.shinshu-u.ac.jp/profile/ja.ypchuUkV.html |
出版者 |
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出版者 |
UNIV CHICAGO PRESS |
引用 |
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内容記述 |
ASTRONOMICAL JOURNAL. 123(4):1847-1863 (2002) |
書誌情報 |
ASTRONOMICAL JOURNAL
巻 123,
号 4,
p. 1847-1863,
発行日 2002-04
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抄録 |
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内容記述 |
We present a modest survey of quasar metal line absorption systems at redshifts 2.3-4.5. Relatively high signal-to-noise ratio (similar to25 pixel(-1)) spectra of 18 quasars at 2 Angstrom FWHM resolution show many absorption systems with strong metal lines in the region redward of the Lyalpha emission lines. We conducted a systematic search and found 55 C IV doublets, 19 Si IV doublets, three Mg II doublets, and seven N v doublets. The present data alone hint that the number of C IV absorption doublets per unit redshift, N(z), decreases with increasing redshift for 2.3 < z < 4.5 but at only the 1-2 sigma level, for either an Einstein de Sitter model (Lambda = 0) or a flat universe with Lambda = 0.7. When we combine our sample with published data that extend to lower redshifts, we detect evolution at the 1-4 sigma level, depending on the cosmological model and the strength of the C IV lines. There are fewer C IV systems per unit z with increasing z, and the systems with stronger C IV lines evolve much faster. At z similar or equal to 2.4, C IV with W > 0.3 Angstrom are approximately 55% of all C IV systems with W > 0.15 Angstrom, but by z similar or equal to 4 that percentage is less than 37%. Similar conclusions were reached by Sargent, Boksenberg, & Steidel and by Steidel, primarily at lower redshifts. However, we measure approximately twice the density of C IV systems at 2.3 < z < 3.8 with W > 0.15 Angstrom that was reported by Steidel. The probability that our sample and previous samples come from the same distribution is only similar to2%. But this could be a statistical accident because it is an a posteriori comparison. We believe that the systems that we report are real, and we have no other explanation for this difference. For Si IV absorption lines, there is a 1 sigma hint of evolution with the same sense. In contrast, Lyalpha and Mg II systems are known to show evolution of the opposite sense with more absorbers at larger redshifts. The physical cause of this difference may be a mixture of ionization and chemical evolution effects. |
資源タイプ(コンテンツの種類) |
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内容記述 |
Article |
ISSN |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
0004-6256 |
書誌レコードID |
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収録物識別子タイプ |
NCID |
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収録物識別子 |
AA00552749 |
権利 |
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権利情報 |
Copyright© 2002 The American Astronomical Society |
出版タイプ |
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出版タイプ |
VoR |
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出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
WoS |
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URL |
http://gateway.isiknowledge.com/gateway/Gateway.cgi?&GWVersion=2&SrcAuth=ShinshuUniv&SrcApp=ShinshuUniv&DestLinkType=FullRecord&DestApp=WOS&KeyUT=000174756400004 |