| http://dbpedia.org/ontology/abstract
|
Damped Lyman alpha systems or Damped Lyman … Damped Lyman alpha systems or Damped Lyman alpha absorption systems is a term used by astronomers for concentrations of neutral hydrogen gas that are detected in the spectra of quasars – a class of distant Active Galactic Nuclei. They are defined to be systems where the column density (density projected along the line of sight to the quasar) of hydrogen is larger than 2 x 1020 atoms/cm2. The observed spectra consist of neutral hydrogen Lyman alpha absorption lines which are broadened by radiation damping. These systems can be observed in quantity at relatively high redshifts of 2–4, when they contained most of the neutral hydrogen in the universe.They are believed to be associated with the early stages of galaxy formation, as the high neutral hydrogen column densities of DLAs are also typical of sightlines in the Milky Way, and other nearby galaxies. Since they are observed in absorption rather than emissions by their stars, they offer the opportunity to study the dynamics of the gas in early galaxies directly.ics of the gas in early galaxies directly.
, 阻尼萊曼α系 或阻尼萊曼α吸收系（Damped Lyman alpha system … 阻尼萊曼α系 或阻尼萊曼α吸收系（Damped Lyman alpha systems, Damped Lyman alpha absorption systems）是在類星體光譜中檢測到的莱曼α阻尼吸收线特征，定义为其相应中性氢气体柱密度大於1020.3原子/公分2，即（）。所觀測到的中性氫萊曼α線因為而使吸收譜線變寬。（；）這些系統因為顯示出很大的紅移而很重要，它們主導了宇宙充滿了中性氫的時期，並且意味著在測量時無需做電離的修正（）。阻尼萊曼α系的高中性氫列密度也在典型的銀河視線方向上，和其他鄰近的星系。因此曾被觀測到的阻尼萊曼α系，在所有的紅移上都被認為是氣體豐富的星系。他鄰近的星系。因此曾被觀測到的阻尼萊曼α系，在所有的紅移上都被認為是氣體豐富的星系。
|
| http://dbpedia.org/ontology/wikiPageID
|
24053946
|
| http://dbpedia.org/ontology/wikiPageLength
|
2524
|
| http://dbpedia.org/ontology/wikiPageRevisionID
|
1098662428
|
| http://dbpedia.org/ontology/wikiPageWikiLink
|
http://dbpedia.org/resource/Category:Intergalactic_media +
, http://dbpedia.org/resource/Lyman-alpha_emitter +
, http://dbpedia.org/resource/Quasar +
, http://dbpedia.org/resource/Redshift +
, http://dbpedia.org/resource/Hydrogen +
, http://dbpedia.org/resource/Galaxy_formation_and_evolution +
, http://dbpedia.org/resource/Radiation_damping +
, http://dbpedia.org/resource/Active_Galactic_Nuclei +
, http://dbpedia.org/resource/Spectrum +
, http://dbpedia.org/resource/Lyman-alpha_blob +
, http://dbpedia.org/resource/Lyman-break_galaxy +
, http://dbpedia.org/resource/Astronomer +
, http://dbpedia.org/resource/Category:Astronomical_spectroscopy +
, http://dbpedia.org/resource/Milky_Way +
, http://dbpedia.org/resource/Lyman-alpha_forest +
, http://dbpedia.org/resource/Category:Physical_cosmology +
, http://dbpedia.org/resource/Lyman_alpha +
|
| http://dbpedia.org/property/wikiPageUsesTemplate
|
http://dbpedia.org/resource/Template:Short_description +
, http://dbpedia.org/resource/Template:Reflist +
, http://dbpedia.org/resource/Template:Physical-cosmology-stub +
|
| http://purl.org/dc/terms/subject
|
http://dbpedia.org/resource/Category:Intergalactic_media +
, http://dbpedia.org/resource/Category:Astronomical_spectroscopy +
, http://dbpedia.org/resource/Category:Physical_cosmology +
|
| http://purl.org/linguistics/gold/hypernym
|
http://dbpedia.org/resource/Concentrations +
|
| http://www.w3.org/ns/prov#wasDerivedFrom
|
http://en.wikipedia.org/wiki/Damped_Lyman-alpha_system?oldid=1098662428&ns=0 +
|
| http://xmlns.com/foaf/0.1/isPrimaryTopicOf
|
http://en.wikipedia.org/wiki/Damped_Lyman-alpha_system +
|
| owl:sameAs |
http://zh.dbpedia.org/resource/%E9%98%BB%E5%B0%BC%E8%90%8A%E6%9B%BC%CE%B1%E7%B3%BB +
, http://dbpedia.org/resource/Damped_Lyman-alpha_system +
, https://global.dbpedia.org/id/4j1Gx +
, http://rdf.freebase.com/ns/m.07k7kgg +
, http://www.wikidata.org/entity/Q5212927 +
, http://yago-knowledge.org/resource/Damped_Lyman-alpha_system +
|
| rdf:type |
http://dbpedia.org/class/yago/YagoLegalActorGeo +
, http://dbpedia.org/class/yago/YagoLegalActor +
, http://dbpedia.org/class/yago/Abstraction100002137 +
, http://dbpedia.org/class/yago/WikicatIntergalacticMedia +
, http://dbpedia.org/class/yago/Company108058098 +
, http://dbpedia.org/class/yago/Group100031264 +
, http://dbpedia.org/class/yago/SocialGroup107950920 +
, http://dbpedia.org/class/yago/YagoPermanentlyLocatedEntity +
, http://dbpedia.org/class/yago/Organization108008335 +
, http://dbpedia.org/class/yago/Institution108053576 +
|
| rdfs:comment |
Damped Lyman alpha systems or Damped Lyman … Damped Lyman alpha systems or Damped Lyman alpha absorption systems is a term used by astronomers for concentrations of neutral hydrogen gas that are detected in the spectra of quasars – a class of distant Active Galactic Nuclei. They are defined to be systems where the column density (density projected along the line of sight to the quasar) of hydrogen is larger than 2 x 1020 atoms/cm2.ydrogen is larger than 2 x 1020 atoms/cm2.
, 阻尼萊曼α系 或阻尼萊曼α吸收系（Damped Lyman alpha system … 阻尼萊曼α系 或阻尼萊曼α吸收系（Damped Lyman alpha systems, Damped Lyman alpha absorption systems）是在類星體光譜中檢測到的莱曼α阻尼吸收线特征，定义为其相应中性氢气体柱密度大於1020.3原子/公分2，即（）。所觀測到的中性氫萊曼α線因為而使吸收譜線變寬。（；）這些系統因為顯示出很大的紅移而很重要，它們主導了宇宙充滿了中性氫的時期，並且意味著在測量時無需做電離的修正（）。阻尼萊曼α系的高中性氫列密度也在典型的銀河視線方向上，和其他鄰近的星系。因此曾被觀測到的阻尼萊曼α系，在所有的紅移上都被認為是氣體豐富的星系。他鄰近的星系。因此曾被觀測到的阻尼萊曼α系，在所有的紅移上都被認為是氣體豐富的星系。
|
| rdfs:label |
阻尼萊曼α系
, Damped Lyman-alpha system
|
