Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measuring the fading of S0 galaxies using globular clusters   We test the hypothesis that S0 galaxies are the descendants of fading spirals
whose star formation has been shut down, by using the properties of their
globular cluster (GC) systems. We estimate the amount by which the GC specific
frequency (number of GCs per unit V-band luminosity) is enhanced in S0s
relative to spirals. If the transformation hypothesis is correct, and no GCs
are created or destroyed in the process, then this difference provides a
measure of the degree to which the S0's V-band luminosity has faded relative to
that of its spiral progenitor. We also explore whether the degree to which the
GC specific frequency is enhanced in S0s correlates with the colour of the
stellar population, as also predicted by this hypothesis in which galaxies
become redder as they fade. We find that, on average, the GC specific frequency
is a factor ~3 larger for S0s than for spirals, which can be interpreted as
meaning that passively-evolving S0s have faded by about a factor of 3 from
their spiral progenitors. This value fits remarkably well with the predictions
of stellar population synthesis calculations, and the offset between the S0 and
spiral Tully-Fisher relations. We also find that the global colours of S0
galaxies are strongly correlated with their GC specific frequencies: the redder
the stellar population of an S0, the larger its specific frequency, as we might
expect if we are catching different S0s at different stages of passively fading
and reddening. Comparison to the predictions of stellar population synthesis
models show that this explanation works quantitatively as well as
qualitatively. These tests strongly support the hypothesis that S0 galaxies
were once normal spirals, whose star formation was cut off, presumably due to a
change of environment.

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The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
5
The categories of this paper are: gr-qc
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The categories of this paper are: q-fin