  We present soft (0.5-2 keV) X-ray luminosity functions (XLFs) in the Great
Observatories Origins Deep Survey (GOODS) fields, derived for galaxies at
z~0.25 and 0.75. SED fitting was used to estimate photometric redshifts and
separate galaxy types, resulting in a sample of 40 early-type galaxies and 46
late-type galaxies. We estimate k-corrections for both the X-ray/optical and
X-ray/NIR flux ratios, which facilitates the separation of AGN from the
normal/starburst galaxies. We fit the XLFs with a power-law model using both
traditional and Markov-Chain Monte Carlo (MCMC) procedures. The XLFs differ
between z<0.5 and z>0.5, at >99% significance levels for early-type, late-type
and all (early and late-type) galaxies.We also fit Schechter and log-normal
models to the XLFs, fitting the low and high redshift XLFs for a given sample
simultaneously assuming only pure luminosity evolution. In the case of
log-normal fits, the results of MCMC fitting of the local FIR luminosity
function were used as priors for the faint and bright-end slopes (similar to
``fixing'' these parameters at the FIR values except here the FIR uncertainty
is included). The best-fit values of the change in log L* with redshift were
dlogL* = 0.23 +/- 0.16 dex (for early-type galaxies) and 0.34 +/- 0.12 dex (for
late-type galaxies), corresponding to (1+z)^1.6 and (1+z)^2.3. These results
were insensitive to whether the Schechter or log-normal function was adopted.

Astrophysics