Descendants of Clusters and Zoom-in Status in TNG-Cluster
Bhuvan Manojh
25 Sep
I have a question relating to time-tracking of clusters and their zoom-in status in TNG-Cluster. My analysis is to calculate the amount of stellar mass formed in-situ for the BCG and ICL in the cores of clusters after ~1 Gyr. To track the descendants, I follow the MPB of the cluster using sublink_gal to get the cluster ID 7 snapshots later. I also check if this descendant is a zoom-in cluster for that snapshot. However, in my samples of about 50 and 250 clusters, I get that 7 and 16 clusters respectively are not zoom-in at later snapshots.
If they are not zoom-in clusters at a future snapshot, is it significant enough to drop them (and subsequently their progenitors) from the sample, or is it acceptable to keep them at the disclaimer that they might not be highly resolved? Is there a recommended method to ensure that these descendants are zoom-in clusters?
Dylan Nelson
28 Sep
How do you select your initial sample?
Perhaps you could (should) take the 352 primary halos at z=0, then follow their main progenitors back to your target redshift, and use these 352 progenitors as your parent sample. It seems that this would avoid the issue you describe.
In addition, could you clarify what "is a zoom-in cluster" means?
By "zoom-in cluster" I mean one of the 352 primary clusters at that snapshot.
My initial sample was selected by iterating through redshifts 1.5-2.44 and adding any clusters satisfying my criteria (SFR in core of cluster above some threshold value), separating based on origin of the star formation (from central subhalos, non-central subhalos or both).
Using the 352 clusters at z=0 is similar to what I did, as I mapped the clusters in my sample to their z=0 descendant along the MDB and connected clusters with the same descendant (which are just the same "unique" clusters over time that were tagged in my sample). However, starting with the 352 main clusters and analyzing their progenitors directly from the merger trees at my desired redshifts seems more robust.
I have a question relating to time-tracking of clusters and their zoom-in status in TNG-Cluster. My analysis is to calculate the amount of stellar mass formed in-situ for the BCG and ICL in the cores of clusters after ~1 Gyr. To track the descendants, I follow the MPB of the cluster using sublink_gal to get the cluster ID 7 snapshots later. I also check if this descendant is a zoom-in cluster for that snapshot. However, in my samples of about 50 and 250 clusters, I get that 7 and 16 clusters respectively are not zoom-in at later snapshots.
If they are not zoom-in clusters at a future snapshot, is it significant enough to drop them (and subsequently their progenitors) from the sample, or is it acceptable to keep them at the disclaimer that they might not be highly resolved? Is there a recommended method to ensure that these descendants are zoom-in clusters?
How do you select your initial sample?
Perhaps you could (should) take the 352 primary halos at z=0, then follow their main progenitors back to your target redshift, and use these 352 progenitors as your parent sample. It seems that this would avoid the issue you describe.
In addition, could you clarify what "is a zoom-in cluster" means?
By "zoom-in cluster" I mean one of the 352 primary clusters at that snapshot.
My initial sample was selected by iterating through redshifts 1.5-2.44 and adding any clusters satisfying my criteria (SFR in core of cluster above some threshold value), separating based on origin of the star formation (from central subhalos, non-central subhalos or both).
Using the 352 clusters at z=0 is similar to what I did, as I mapped the clusters in my sample to their z=0 descendant along the MDB and connected clusters with the same descendant (which are just the same "unique" clusters over time that were tagged in my sample). However, starting with the 352 main clusters and analyzing their progenitors directly from the merger trees at my desired redshifts seems more robust.
Thank you so much for the help!