when I use the subbox to focus on high time resolution, I try to use the subfindID or subhaloID read from fullbox's merger tree. But I failed.
So what should I do to identify the subhalos in subbox which I have get from the fullbox?
Dylan Nelson
7 Apr
There are no catalogs for the subboxes.
So if you have a (sub)halo from a fullbox snapshot at the same time, you could e.g. use its position, and go to that location in space.
Xu Li
16 Apr
Dear Sir,
I just try to read the mass of the subhalo in subbox , but its value is zero in some snapshot. Why?
Dylan Nelson
16 Apr
Can you please post your exact code, and the output.
No subhalo has zero total mass, since subhalos have a minimum of 20 particles/cells, each of which has mass.
Xu Li
17 Apr
the masses of gas , black holes and stars is 0. And for dark matter, should I still use the snapshot.loadsubhalo this function to get?
Dylan Nelson
17 Apr
Many subhalos have zero gas, stellar, and SMBH mass, i.e. they have only DM mass. These are typically low mass.
Xu Li
17 Apr
Thanks for your replying, Sir.
And how to read their DM mass? I try using function in snapshot like, il.snapshot.loadSubhalo, but failed.
If I need to read the snapdir_subbox0 these file , does there are some way to know which DM particles belong to the subhalo?
Dylan Nelson
17 Apr
If you are referring to a subbox snapshot, then there are no catalogs, so there are no subhalos.
The values in the "SubboxSubhaloList" catalog are obtained by going to the spatial position of the subhalo (using the catalogs from the full snapshot), loading all particles, and looking at those particles within a given distance from the position of the center of the subhalo. You could then sum their masses.
when I use the subbox to focus on high time resolution, I try to use the subfindID or subhaloID read from fullbox's merger tree. But I failed.
So what should I do to identify the subhalos in subbox which I have get from the fullbox?
There are no catalogs for the subboxes.
So if you have a (sub)halo from a fullbox snapshot at the same time, you could e.g. use its position, and go to that location in space.
Dear Sir,
I just try to read the mass of the subhalo in subbox , but its value is zero in some snapshot. Why?
Can you please post your exact code, and the output.
No subhalo has zero total mass, since subhalos have a minimum of 20 particles/cells, each of which has mass.
the masses of gas , black holes and stars is 0. And for dark matter, should I still use the snapshot.loadsubhalo this function to get?
Many subhalos have zero gas, stellar, and SMBH mass, i.e. they have only DM mass. These are typically low mass.
Thanks for your replying, Sir.
And how to read their DM mass? I try using function in snapshot like, il.snapshot.loadSubhalo, but failed.
If I need to read the snapdir_subbox0 these file , does there are some way to know which DM particles belong to the subhalo?
If you are referring to a subbox snapshot, then there are no catalogs, so there are no subhalos.
The values in the "SubboxSubhaloList" catalog are obtained by going to the spatial position of the subhalo (using the catalogs from the full snapshot), loading all particles, and looking at those particles within a given distance from the position of the center of the subhalo. You could then sum their masses.