Can't find where the frequency of /odom and /scan topic are set on turtlebot3_gazebo

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Hello!

I'm a bit new in ros. I'm doing a work where I use turtlebot3 in gazebo and I need to get the data of the topic /odom a /scan. I'm using rosbag and I'm being successful in getting the data, but both are in different frequency, and I need them in same frequency.

I know it is from node /gazebo but I really can find where this frequencies are set. I search everywhere but I'm noob yet so maybe I didn't search on the right place. someone can help, please?

Thanks for your help