Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Surface Brightness and Colour-Magnitude Relations for Fornax Cluster
  Galaxies   We present BVI photometry of 190 galaxies in the central region of the Fornax
Cluster observed with the Michigan Curtis Schmidt Telescope. The cluster
members exhibit a strong surface brightness-magnitude relation in our data:
both giant and dwarf ellipticals decrease in surface brightness as luminosity
decreases. However the surface brightness-magnitude relation is no longer a
reliable method for determining cluster membership at surface brightnesses
fainter than 22 mag/sq.arcsec. The newly discovered ultra-compact dwarf
galaxies (UCDs) lie well off the normal surface brightness-magnitude relation.
We present the colour-magnitude relation for a sample of 113 cluster galaxies
as a function of morphological type. The UCDs also lie off the locus of this
relation. Their mean V-I colours are redder than dwarf galaxies of similar
luminosity, but similar to those of globular clusters associated with NGC 1399.
The location of the UCDs on both surface brightness and colour-magnitude plots
supports the hypothesis that they are the remnants of tidally stripped
nucleated dwarf elliptical galaxies.

23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas