Contents of: VI/111/./abstract/JDUNLOP_HZRGDHH.abs

The following document lists the file abstract/JDUNLOP_HZRGDHH.abs from catalogue VI/111.
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==> In this proposal, more time is being requested for JDUNLOP.HZRGJSD
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Elliptical galaxies are thought to have formed most of their stars in a rapid
burst at high redshift, but an unambiguous example of a primeval elliptical
has yet to be discovered. High redshift radio galaxies provide the most
promising candidates, but the presence of an active nucleus complicates the
analysis of their evolutionary state from optical observations. We have
therefore recently embarked on a programme to search for thermal emission from
dust in radio galaxies at z > 2 using ground-based sub-millimetre photometry
(Hughes 1996, Hughes etal. 1996).  We have already detected two sources
(Dunlop et al. 1994) and expect to detect many more with more sensitive sub-mm
arrays. However, for an accurate determination of dust mass it is vital that
these sub-mm observations be complemented by ISO photometry at shorter
wavelengths to enable us to constrain the temperature distribution of the
dust.  We were awarded time in the 1st ISO call to observe two high-z radio
galaxies (6C0032+412, z=3.7 & 53W002, z=2.4), however at the time of writing
we have still not received any data.  In this proposal we request sufficient
time to make ISOPHOT observations of an additional 9 high-redshift radio
galaxies at 90um and 160um (corresponding to rest-frame wavelengths of
approximately 25um, and 40um respectively), allowing us to place all results
on a firmer statistical footing.
Our sample has been selected to be representative of the range of properties
(e.g. radio luminosity, radio spectral index, radio morphology, optical
continuum shape, line luminosity etc) found in high-redshift radio galaxies to
date. Most importantly it spans a factor of 1000 in radio power, a fact which
will enable us to unambiguously separate the influence of AGN activity from
the general underlying cosmological evolution. These observations will provide
the first clear picture of the level of star-formation activity in elliptical
galaxies at z=2-5.