Gyroscope Bandwidth on LSM9DS1
Check section 2.7 of the datasheet.

The bandwidth (actually, the cutoff of the low pass filter) is automatically set depending the the output data rate (ODR) that you select.  There is a chart (actually two, as it also depends on the power save mode) that shows the cut off frequencies for the various ODRs.

The datasheet is written bit strangely.  The text keeps talking about "bandwidth" when the tables are all about "cutoffs."

Since the LSM9DS1 also has a high pass filter, the bandwidth would be the difference between the selected highpass and low pass filters.