I am facing gazebo and rviz crash sometimes but in terminal it shows like below.Can you please help me how to get that log file,so that i came to know for what reason it crashed.

[gazebo_gui-3] process has died [pid 16577, exit code 139, cmd /home/zahraa/catkin_ws/src/gazebo_ros_pkgs/gazebo_ros/scripts/gzclient __name:=gazebo_gui __log:=/home/zahraa/.ros/log/4139ed3a-13e2-11e3-9765-6c626d02622d/gazebo_gui-3.log]. log file: /home/zahraa/.ros/log/4139ed3a-13e2-11e3-9765-6c626d02622d/gazebo_gui-3*.log