roscore will be started by a launch file if it is not already running. Also, I have always believed that it will get shut down, together with all nodes, by hitting CTRL-C on the corresponding terminal.

However, in this question, I started roscore through a launchfile, and after i hit CTRL-C, it seems that although all nodes have been shut down, roscore did not, since I could still see 1. /rosout, 2. parameters on parameter server.

Is there a reason why?

Thanks, Rico