You will need to convert your unmanaged array to a managed array.  
Fortunately there is a class in the System::Runtime::InteropServices
namespace that will help with this called Marshal.  Here is code snippet that
should work:

property array<int>^ ManagedArr{
 array<int>^ get()  {
   //We need to create an IntPtr that wraps arr in order to use Marshal
  IntPtr arrPtr(arr);
  array<int>^ managedArr = gcnew array<int>(ARRAY_SIZE);
  Marshal::Copy(arrPtr, managedArr, 0, ARRAY_SIZE);
  return arrPtr;
 }
}