We have determined luminosity functions, surface density distributions
and color distributions for galaxies in eight clusters of galaxies at moderate
redshift (z ~ 0.02) observed at the CFHT.
1) In the inner 2' of four cD clusters (Abell 2052, 2107, 2199 and 2666) we
find very steep LFs, with α ~ -2.2 ± 0.2, where [special characters omitted](L) α Lα, where L is luminosity
2) For Abell 262, we find no significant contribution from cluster dwarfs
in the field around NGC708 (the central cluster elliptical), although
there is a small excess over background counts in the inner 3' of this
field. For galaxies near UGC1308, we derive a LF with α ~ -1.4 ± 0.1.
Galaxies in this field are concentrated towards UGC1308, so that the
LF may be due to a population of satellites.
3) For the field centred on NGC1275 in Abell 426 we find a very steep
LF, with α ~ -1.9 ± 0.1. We find that galaxies are not centrally
concentrated towards NGC1275, except for a central ‘spike’ in their
surface density distribution. We see a weak sequence of galaxies in the
V vs V - I plot. There is a small color gradient in the sense of bluer
galaxies near NGC1275.
4) For the field centred on NGC1265, we find again a very steep LF.
Galaxies in this field tend to avoid the neighbourhood of NGC1265
and there is a mild red color gradient towards NGC1265. The LF
within 100 kpc of NGC1265 is somewhat flatter than outside of this
region, although the significance of this result is marginal.
5) For the field centred on UGC3274 in A539 we find a LF with α ~
-1.4 ± 0.1. We see that the galaxy distribution as a function of distance
from UGC3274 is flat, except for a central spike. The LF appears to
steepen towards UGC3274. There is a tight sequence of cluster galaxies
in the V vs. V - I plot. There also appears to be a blueing trend
towards UGC3274.
6) For Hercules (A2151) we derive a LF with α ~ -1.5 and M* = 12.2,
where M* is a characteristic luminosity here converted to magnitudes.
We interpret these results as supporting the conclusions by Biviano et al.
(1995b) in Coma, namely that a population of dwarf galaxies with a steep
LF constitutes the main body of the cluster, into which brighter giants fall
later, thereby flattening the LF. We also find evidence that steep LFs are
correlated with high gas densities. The blueing trend towards NGC1275
and UGC3274 is also consistent with recent star formation in dwarfs due to
accretion of intracluster gas. / Graduate
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/9700 |
| Date | 13 July 2018 |
| Creators | De Propris, Roberto |
| Contributors | Pritchet, Christopher J. |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
| Rights | Available to the World Wide Web |
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