I am trying to understand where exactly the BH particles are seeded.
According to section 2.2 of this paper (https://ui.adsabs.harvard.edu/abs/2017MNRAS.465.3291W/abstract), once a halo reaches the minimum M_FoF for seeding, you put a black hole in its center and try to avoid it leaving the halo by making it go to the potential minimum.
In the paper is said that once a halo crosses the mass threshold a black hole "is placed at the centre of a halo". Question: Does "centre" means the centre of mass or the potential minimum?
The new SMBH replaces the gas cell with the highest density (in the FoF halo).