We found few subhalos are omitted from SubLinkTree.
We tried to find their descendant with stellar particles and most of them have appropriate(?) descendants. But this method consumes a lot of time, is there any suitable information for those subhalos?
Dylan Nelson
26 Mar
Can you provide a specific example (simulation, snapshot ID, subhalo ID, and descendant/progenitor subhalo ID at adjacent snapshot).
Seungwu Yoo
28 Mar
I used TNG 300-1
I found that all subhalos (M_*>1e9Msun) with SubhaloFlag==0 in snapshot 99 (z=0) are not associated in SubLinkTree. (I found the message kind of "Warning, empty return. Subhalo [890] at snapNum [99] not in tree.")
When I also tried to find the descendant of subhalo in higher redshift snapshots (their SubhaloFlag are 1), I also found same situations.
For example, I found subhalo ID 1205 in snapshot 34 is not associated in the tree. I found that 91.2% stellar particles of subhalo 1205 are associated in subhalo 1212 in next snapshot.
Seungwu Yoo
30 Mar
I apologize for my mistake. I found that some subhalos with SubhaloFlag=0 (M_*>1e9Msun) belong to the tree! But most (about 75%) of them are still not member of tree.
Dylan Nelson
30 Mar
The SubLink trees are based on cross-matching of dark matter particles, and Subhalo 1205 TNG300-1 snap 34 has none, so it cannot have any progenitors/descendants, by definition.
If you are specifically needing to track low-mass galaxies that may be devoid of DM, then you are right that tracking via star IDs may be more useful.
In fact there is an alternative version of SubLink that does this, it is called SubLink_gal. We did not make this initially available for public download, but as it is a fairly common request, it is available in the Lab, under postprocessing/trees/SubLink_gal. Perhaps this would be useful to look at.
We found few subhalos are omitted from SubLinkTree.
We tried to find their descendant with stellar particles and most of them have appropriate(?) descendants. But this method consumes a lot of time, is there any suitable information for those subhalos?
Can you provide a specific example (simulation, snapshot ID, subhalo ID, and descendant/progenitor subhalo ID at adjacent snapshot).
I used TNG 300-1
I found that all subhalos (M_*>1e9Msun) with SubhaloFlag==0 in snapshot 99 (z=0) are not associated in SubLinkTree. (I found the message kind of "Warning, empty return. Subhalo [890] at snapNum [99] not in tree.")
When I also tried to find the descendant of subhalo in higher redshift snapshots (their SubhaloFlag are 1), I also found same situations.
For example, I found subhalo ID 1205 in snapshot 34 is not associated in the tree. I found that 91.2% stellar particles of subhalo 1205 are associated in subhalo 1212 in next snapshot.
I apologize for my mistake. I found that some subhalos with SubhaloFlag=0 (M_*>1e9Msun) belong to the tree! But most (about 75%) of them are still not member of tree.
The SubLink trees are based on cross-matching of dark matter particles, and Subhalo 1205 TNG300-1 snap 34 has none, so it cannot have any progenitors/descendants, by definition.
If you are specifically needing to track low-mass galaxies that may be devoid of DM, then you are right that tracking via star IDs may be more useful.
In fact there is an alternative version of SubLink that does this, it is called
SubLink_gal. We did not make this initially available for public download, but as it is a fairly common request, it is available in the Lab, underpostprocessing/trees/SubLink_gal. Perhaps this would be useful to look at.