  We present new Chandra observations of the outer halo of the giant elliptical
galaxy NGC 4472 (M49) in the Virgo Cluster. The data extend to 130 kpc (28'),
and have a combined exposure time of 150 ks. After identifying optical
counterparts using the Next Generation Virgo Cluster Survey to remove
background active galactic nuclei and globular cluster (GC) sources, and
correcting for completeness, we find that the number of field low-mass X-ray
binaries (LMXBs) per unit stellar V-band light increases significantly with
galactocentric radius. Because the flux limit of the complete sample
corresponds to the Eddington limit for neutron stars in NGC 4472, many of the
~90 field LMXBs in this sample could host black holes. The excess of field
LMXBs at large galactocentric radii may be partially caused by natal kicks on
black holes and neutron stars in binary systems in the inner part of the
galaxy. Furthermore, since the metallicity in the halo of NGC 4472 strongly
decreases towards larger galactocentric radii, the number of field LMXBs per
unit stellar mass is anti-correlated with metallicity, opposite to what is
observed in GCs. Another way to explain the spatial distribution of field LMXBs
is therefore a reversed metallicity effect, although we have not identified a
mechanism to explain this in terms of stellar and binary evolution.
