I am writing to ask you about any flags that distinguish between satellite galaxies and central galaxies in Illustris-TNG 50-1.
I am currently trying to understand the dynamics of the Milky Way - like galaxies from the following list of subhalo IDs.https://www.tng-project.org/data/milkyway+andromeda/ using radial distance vs radial velocity phase space.
I have downloaded Redshift 0 snapshots. Since the central galaxies are not isolated, the satellite galaxies are creating 'noise' in the plots like radial velocity vs radius. Hence, I was wondering if there is a way to distinguish central and satellite galaxy particles. So far, I have tried to use subfindhsml values to identify very dense regions ( with the threshold value of 4.0 - hit and trial value) to isolate central galaxy particles, however, it is not as clean.
Could you kindly let me know if there is a way to change that?
Thanks for taking the time :)
Best,
Anisha
University of Hamburg
Dylan Nelson
23 Aug
Yes, all subhalos, including satellite subhalos, are made up of constituent member particles/cells. So you can identify these, and exclude them when e.g. making a radial profile, if you wish.
Each particle/cell does not explicitly record its parent subhalo. Instead, this membership is understood via the index of the particle/cell, as discussed more in the pinned thread.
Hi Dr. Nelson,
I am writing to ask you about any flags that distinguish between satellite galaxies and central galaxies in Illustris-TNG 50-1.
I am currently trying to understand the dynamics of the Milky Way - like galaxies from the following list of subhalo IDs.https://www.tng-project.org/data/milkyway+andromeda/ using radial distance vs radial velocity phase space.
I have downloaded Redshift 0 snapshots. Since the central galaxies are not isolated, the satellite galaxies are creating 'noise' in the plots like radial velocity vs radius. Hence, I was wondering if there is a way to distinguish central and satellite galaxy particles. So far, I have tried to use subfindhsml values to identify very dense regions ( with the threshold value of 4.0 - hit and trial value) to isolate central galaxy particles, however, it is not as clean.
Could you kindly let me know if there is a way to change that?
Thanks for taking the time :)
Best,
Anisha
University of Hamburg
Yes, all subhalos, including satellite subhalos, are made up of constituent member particles/cells. So you can identify these, and exclude them when e.g. making a radial profile, if you wish.
Each particle/cell does not explicitly record its parent subhalo. Instead, this membership is understood via the index of the particle/cell, as discussed more in the pinned thread.