Catalog of X-ray sources in NGC 4278

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 L_X_ from 3.5x10^36^erg/s (with 3{sigma} upper limit <=1x10^37^erg/s) to ~2x10^40^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 GC, these sources tend to have high X-ray luminosity, with 10 of these sources exhibiting L_X_>1x10^38^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 low-mass X-ray binary spectra, with 29 of these sources expected to be background objects from the log N-log S relation.