# B How does one compute frequency bandwidth based on FWHM

1. Jan 6, 2017

and this is in the local standard of rest (LSR), $v_{LSR}$. I have seen basic doppler shift equations to convert from these velocities to frequency (shown below in link). Although if I consider the bandwidth to be 2 km/s and the frequency of 1720 MHz to correspond to ~-45 km/s, then the frequency bandwidth would be on the order of 100 MHz which doesn't seem to be quite right intuitively as masers are typically much narrower. Also, in the paper, they state they observe another OH line at ~30 km/s so I don't believe my above interpretation is correct.