  We have identified a sample of 10 highly reliable off-nuclear (> 2 kpc) X-ray
sources at z=0.03-0.25 in late-type host galaxies within the two GOODS fields
(i.e., the two Chandra Deep Fields). The combination of the superb spatial
resolution and great depth of the HST ACS and Chandra ACIS coverage in the
GOODS fields is critical to the identification of these sources. We extend the
study of this enigmatic population up to higher redshifts and larger look-back
times than has been possible before, finding that the fraction of optically
luminous galaxies exhibiting luminous off-nuclear sources at z~0.1 is larger
than at the current time (~36% versus ~8%). The X-ray luminosities of the GOODS
off-nuclear X-ray sources are comparable to or slightly greater than the
integrated point-source X-ray luminosities of nearby galaxies, providing a
possible constraint on the X-ray Luminosity Function at higher star-formation
rates. X-ray variability demonstrates that several of these sources are likely
single accreting black holes; for the majority, however, the number of X-ray
counts is too low for X-ray variability studies.
