Simple 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.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/623813 |
| Date | 11 1900 |
| Creators | Weymann, R. J. |
| Contributors | Univ Arizona, Steward Observ |
| Publisher | Steward Observatory, The University of Arizona (Tucson, Arizona) |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Article |
| Source | Steward Observatory Parker Library SO QB 4 .S752 ARCH |
| Rights | Copyright © All Rights Reserved. |
| Relation | Preprints of the Steward Observatory #6 |
Page generated in 0.0029 seconds