Does 'depth-first' in SubLink tree equal to 'main-branch'?

怡远 张
  • 19 Jul

Hello!
I noticed that the field SubhaloID is assigned in a 'depth-first' fashion,does it mean that what comes first is on the main branch?For example,for TNG100-1,I obtain the SubfindID is [0(snapshot99), 0(snapshot98), 0(snapshot97), 0(snapshot96), 0(snapshot95), 0(snapshot94) ,13296(snapshot93), 13269, 13200, 13164, 13186, 13119, 13212, 13089, 13057, 13069, 0(snapshot83), 0(snapshot82), 0, 19818, 19482, 9162, 8834, 0,...]using il.sublink.loadTree(basePath, 99, 0, fields=None, onlyMPB=False, onlyMDB=False, treeName="SubLink", cache=True).Can I understand that as although there're 1489 subhalos in snapshot98 merged into subhalo0 in snapshot99,the subhalo0 in sanpshot98 is on the main branch,i.e.the central subhalo,and the other 1488 subhalos mergered into this subhalo.If so,why there's a 'vanishment' in snapshot93 and 're·appearance' in snapshot83?In other words,the switch of 13296(snapshot93) to 0(snapshot94) means the subhalo13296(snapshot93) mergerd with other subhalos and renumbered as subhalo0 in snapshot94,or subhalo13296(snapshot93)mergered into a subhalo named subhalo0 in snapshot93 ,if it is later, that means 'depth-first' is not equal to 'main branch' .
Looking forward to your reply!
Best wishes!
Zhang

Dylan Nelson
  • 21 Jul

Yes, the MPB (main progenitor branch) "comes first" in a given tree.

I hope this is clear from the schematic diagram.

怡远 张
  • 22 Jul

OK,thank you very much!

  • Page 1 of 1