Differences with van Dokkum & Franx (2001)
Equation (1) in the paper has been implemented as
P(tstop) ∝ exp((tstart-t)/τ)
to account for the fact that tstart can be >0
The time between cessation of star formation and morphological transformation
to early-type galaxy is now a free parameter. In the paper this time
was fixed at 0.1 x the age of the Universe, i.e., ~1.4 Gyr. It can
now be set at any value; defaults
are 0 for the "Default 1" model and
0.1 for the "Default 2" and "Default 3" models.
The paper only gives expressions for luminosity evolution in B
and color evolution in U - B. Filters from U through
K are offered here.
The default cosmology in the paper has Ωm=0.3,
ΩΛ=0, although results for a Λ cosmology
are also given. The calculator uses the "standard"
Ωm=0.3, ΩΛ=0.7 cosmology. Note that
the calculation is fully independent of the value of H0.
The values of κ (which describe the age-dependence of
the luminosity in a given passband) are now determined from the
Bruzual & Charlot (2003) models, using a Salpeter IMF and Solar
metallicity. As described in the Help to the filters,
other IMF's or metallicities can be accomodated as well.
The output is expanded with respect to the plots given in the paper:
results are given out to z=3 rather than z=1, and the mean formation
redshift of the stars in early-type galaxies at each epoch is
now provided.
Note that more discussion on these topics is given in the Help links.