We search for signatures of past accretion events in the Milky Way in the recently published catalogue by Nordström et al .
( 2004 ) , containing accurate spatial and kinematic information as well as metallicities for 13240 nearby stars .
To optimize our strategy , we use numerical simulations and characterize the properties of the debris from disrupted satellites .
We find that stars with a common progenitor should show distinct correlations between their orbital parameters ; in particular , between the apocentre A and pericentre P , as well as their z -angular momentum ( L _ { z } ) .
In the APL-space , such stars are expected to cluster around regions of roughly constant eccentricity .

The APL space for the Nordström catalogue exhibits a wealth of substructure , much of which can be linked to dynamical perturbations induced by spiral arms and the Galactic bar .
However , our analysis also reveals a statistically significant excess of stars on orbits of common ( moderate ) eccentricity , analogous to the pattern expected for merger debris .
Besides being dynamically peculiar , the 274 stars in these substructures have very distinct metallicity and age distributions , providing further evidence of their extra-Galactic provenance .
It is possible to identify three coherent Groups among these stars , that , in all likelihood , correspond to the remains of disrupted satellites .
The most metal-rich group ( [ Fe/H ] > -0.45 dex ) has 120 stars distributed into two stellar populations of \sim 8 Gyr ( 33 % ) and \sim 12 Gyr ( 67 % ) of age .
The second Group with \langle [ Fe/H ] \rangle \sim - 0.6 dex has 86 stars , and shows evidence of three populations of 8 Gyr ( 15 % ) , 12 Gyr ( 36 % ) and 16 Gyr ( 49 % ) of age .
Finally , the third Group has 68 stars , with typical metallicity around -0.8 dex , and a single age of \sim 14 Gyr .
The identification of substantial amounts of debris in the Galactic disk whose origin can be traced back to more than one satellite galaxy , provides evidence of the hierarchical formation of the Milky Way .