'systemd-coredumpctl' will list available coredumps:
   PID   UID   GID sig exe
 32452  500  500  11 /home/zbyszek/systemd/build/journalctl
 32666  500  500  11 /usr/lib64/valgrind/memcheck-amd64-linux
...

'systemd-coredumpctl dump PID' will write the coredump
to specified file or stdout.