The SystemTracer runs through the system tracing every accessible object, and writing a copy of each object onto a disk image. It does this carefully enough that the resulting clone can be started up and run, just like a snapshot. See SystemTracer class comment for background.
To trace the current running image, producing an equivalent clone image:
SystemTracer2 writeImage: 'newImageFile.image'
To trace the current running image, producing an new image in an experimental 64-bit object memory format:
SystemTracer64 writeImage: 'new64BitImageFile.image'
Note that a 64-bit image format requires a standard interpreter VM compiled for that image format (for unix builds, this is the --image64 option for the cmake configure script). See for information on 64-bit images and VMs.