[yt-users] questions about halo profiling

[Irina Dvorkin]

Hello All,

After reading the halo profiler python files, I got the impression  
that it reads the position of the halo center and then approximates  
the halo to a sphere with this center, and so includes some mass that  
is actually not in the halo (for example if the halo is an ellipsoid).  
My knowledge of python, however, is rather poor, so it would help me a  
lot if you could tell me whether my understanding is correct.

Also, I noticed that both the halo profiler and the halo finder use a  
non-standard definition of the virial radius: usually it is defined as  
the radius that encompasses a region that is, say, 200 (or other  
number) times denser than the *critical* density at that redshift. The  
definition in the halo profiler is 200 (or other number) times the  
density of *matter*. So I would suggest to specifically mention this  
definition in the manual because it can cause confusion.

Thanks,
Irina