This map is stored in RAM memory - it is created by gmapping node and it will persist as long as this node is running.
The best way to store the map is to use
rosrun map_server map_saver.
gmapping node is publishing map as
nav_msgs/OccupancyGrid message type in topic
/map. When you call
map_saver it subscribes to
/map topic to get single message, saves it to
map.pgm and its metadata to
To use created map in the same launch, you need to disable
<node pkg="rosbot_webui" type="gmapping_supervisor.py" name="gmapping_supervisor" output="screen"/>
It is located in line 24 (comment it out or delete), then add line:
<node pkg="map_server type="map_server" name="map_server" output="screen" args="map.yaml"/>
Probably you will want also localization for this map, you could use amcl.