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dc.contributor.authorWeymann, R. J.
dc.date.accessioned2017-06-02T17:57:30Z
dc.date.available2017-06-02T17:57:30Z
dc.date.issued1966-11
dc.identifier.urihttp://hdl.handle.net/10150/623813
dc.description.abstractSimple models for bright, helium producing phases in the lives of massive galaxies are used to investigate the distance out to which they could be seen as individual objects. Roughly speaking, objects radiating at effective temperatures of ..;40,000 o could be detected out to redshifts as large as 8 -+12. Such redshifts correspond to densities at which we might reasonably have expected galaxy condensation to occur, except possibly for the lowest part of the probable range of go-values. Such Objects ought to be bluer than ordinary "nearby" galaxies, and for open cosmological models would be expected to be much more numerous than ordinary galaxies; for closed models the numbers of bright and ordinary galaxies should be comparable. The feasibility of detecting such objects by ground -based measures of their integrated skybrightness in the L and M windows is discussed, and it appears that such a technique would be feasible and superior to direct photographic detection only for relatively low effective temperatures in the 20,000 to 1+0,000 range. The possibility of explaining the lack of general Ljy -c4 absorption in distant WO as due to a high degree of ionization brought about by W radiation from these bright galaxies is investigated. The conclusion is that this mechanism will not usually be adequate -- and when it is adequate, the objects causing the ionization should be detectable -- unless the current mean density of uncondensed gas is very low, of the order of 10 -7 particles /cm3 or less.
dc.language.isoen_USen
dc.publisherSteward Observatory, The University of Arizona (Tucson, Arizona)en
dc.relation.ispartofseriesPreprints of the Steward Observatory #6en
dc.rightsCopyright © All Rights Reserved.en
dc.sourceSteward Observatory Parker Library SO QB 4 .S752 ARCHen
dc.subjectModelsen
dc.subjectGalaxiesen
dc.subjectObserving techniquesen
dc.subjectIntergalactic matteren
dc.subjectIonizationen
dc.titleDetectability of Distant Galaxies During a Hypothetical Bright Phase and the Associated Ionization of Intergalactic Matteren_US
dc.typetexten
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Steward Observen
dc.description.collectioninformationThis title from the Steward Observatory Preprints collection is made available by the Steward Observatory Parker Library and the University Libraries, The University of Arizona. If you have questions about titles in this collection, please contact Parker Library librarian Betty Fridena, bfridena@as.arizona.edu.en
refterms.dateFOA2018-09-11T19:46:26Z
html.description.abstractSimple models for bright, helium producing phases in the lives of massive galaxies are used to investigate the distance out to which they could be seen as individual objects. Roughly speaking, objects radiating at effective temperatures of ..;40,000 o could be detected out to redshifts as large as 8 -+12. Such redshifts correspond to densities at which we might reasonably have expected galaxy condensation to occur, except possibly for the lowest part of the probable range of go-values. Such Objects ought to be bluer than ordinary "nearby" galaxies, and for open cosmological models would be expected to be much more numerous than ordinary galaxies; for closed models the numbers of bright and ordinary galaxies should be comparable. The feasibility of detecting such objects by ground -based measures of their integrated skybrightness in the L and M windows is discussed, and it appears that such a technique would be feasible and superior to direct photographic detection only for relatively low effective temperatures in the 20,000 to 1+0,000 range. The possibility of explaining the lack of general Ljy -c4 absorption in distant WO as due to a high degree of ionization brought about by W radiation from these bright galaxies is investigated. The conclusion is that this mechanism will not usually be adequate -- and when it is adequate, the objects causing the ionization should be detectable -- unless the current mean density of uncondensed gas is very low, of the order of 10 -7 particles /cm3 or less.


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