Start independend gui application form notebook

Hello,

I try to start an graphic application like gedit from a notebook.
Woks fine so fare.

But if I “interrupt the kernel” all started application will closed immediately without the chance to saving anything.

I tried many thinks like:
os.system()
subprocess.Popen()
os.fork() …
os.execl()

nothing changed the behavior

on bash terminal multiplexer like screen works fine
example:
os.system(“screen gedit”)
in python command line is works to, can close command line and gedit still works
but from notebook gedit did not open

Is there a way to start a application independently,
so if I interrupt the kernel, application is not effected?