Hope everything is going well!
I need the gas disk or stellar disk rotational velocity of galaxies in unit of the circular velocity. I wonder is there anyway to find this information in TNG50 and TNG300?
Thank you very much for your help!!
The only catalog value related to rotation velocity is SubhaloVmax described as "Maximum value of the spherically-averaged rotation curve".
If you want an actual rotation velocity of gas or stars, you would need to compute this yourself from the particle data. You could follow a procedure similar to that in Pillepich+2019 (page 8) for example.