I've been running some Python scripts to graph some stuff and occasionally I'll lose track of what windows it spawned and just kill it with ^Z. However, unlike in Windows, the associated windows don't die; they stick around and cannot be closed.

These windows seem clueless; they don't redraw after being minimized or resized. I'm new to the Linux env so I can't fully articulate what's going on, but in any event, how do I get rid of these zombie-orphan-hobo windows?