Deep Chandra Monitoring Observations of NGC 4278: Catalog of Source
  Properties
  We present the properties of the discrete X-ray sources detected in our
monitoring program of the globular cluster (GC) rich elliptical galaxy, NGC
4278, observed with Chandra ACIS-S in six separate pointings, resulting in a
co-added exposure of 458-ks. From this deep observation, 236 sources have been
detected within the region overlapped by all observations, 180 of which lie
within the D25 ellipse of the galaxy. These 236 sources range in Lx from 3.5E36
erg/s (with 3sigma upper limit <1E37 erg/s) to ~2E40 erg/s, including the
central nuclear source which has been classified as a LINER. From optical data,
39 X-ray sources have been determined to be coincident with a globular cluster,
these sources tend to have high X-ray luminosity, with ten of these sources
exhibiting Lx>1E38 erg/s. From X-ray source photometry, it has been determined
that the majority of the 236 point sources that have well constrained colors,
have values that are consistent with typical LMXB spectra, with 29 of these
sources expected to be background objects from the logN-logS relation. There
are 103 sources in this population that exhibit long-term variability,
indicating that they are accreting compact objects. 3 of these sources have
been identified as transient candidates, with a further 3 possible transients.
Spectral variations have also been identified in the majority of the source
population, where a diverse range of variability has been identified,
indicating that there are many different source classes located within this
galaxy.
