  The radio-quiet neutron star 1E1207.4-5209 has been the target of several
XMM-Newton observations, with a total exposure of ~350 ks. The source is
located at intermediate galactic latitude (b~10 degrees), i.e. in a sky region
with an extremely interesting mix of both galactic and extra-galactic X-ray
sources. The aim of our work is to investigate the properties of both the
intermediate-latitude galactic and extra-galactic X-ray source populations in
the 1E1207.4-5209 field. We performed a coherent analysis of the whole
XMM-Newton observation data set to build a catalogue of serendipitous X-ray
sources detected with high confidence and to derive information on the source
flux, spectra, and time variability. In addition, we performed a complete
multi-band (UBVRI) optical coverage of the field with the Wide Field Imager
(WFI) of the ESO/MPG 2.2m telescope (La Silla) to search for candidate optical
counterparts to the X-ray sources, down to a V-band limiting magnitude of
~24.5. We detected a total of 144 serendipitous X-ray sources. Thanks to the
refined X-ray positions and to the WFI observations, we found candidate optical
counterparts for most of the X-ray sources in our compilation. For most of the
brightest ones we proposed a likely classification based on both the X-ray
spectra and the optical colours. Our results indicate that at intermediate
galactic latitude the X-ray source population is dominated by the
extra-galactic component, but with a significant contribution from the galactic
component in the soft energy band, below 2 keV.
