  Narrow-band spectral imaging with sub-pixel resolution of the Chandra-ACIS
archival observation of the ULIRG merger Arp 220 strongly suggests two Compton
thick nuclei, spatially coincident with the infrared and radio emitting nuclear
clusters, and separated by 1" (~ 365 pc at a distance of 76 Mpc). These
previously undetected highly obscured AGNs - West (W) and East (E) - are
imaged, and separated from neighboring sources, in the 6-7 keV band, where the
Fe-K lines dominate the emission. The western nucleus is also detected at
energies above 7 keV. We estimate Fe-K equivalent width ~ 1 keV or possibly
greater for both sources, and observed 2-10 keV luminosities L_X < 3.2 x 10^40
erg/s (W) and <1.3 x 10^40 erg/s (E). From the observed Fe-K lines
luminosities{, and assuming on the basis of the XMM-Newton spectrum that 40% of
this may be from the 6.4 keV component, we evaluate 2-10 keV intrinsic
luminosities L_X ~ 1 x 10^42 erg/s (W) and L_X ~ 0.4 x 10^42 erg/s (E). The
inferred X-ray luminosity is at least a factor of 3 higher than that expected
from a pure starburst with the bolometric luminosity of Arp 220. For a typical
AGN SED the bolometric luminosities are 5.2 x 10^43 erg/s (W) and 2 x 10^42
erg/s (E).
