Public Data Access Overview / Discussion Forum

I search a particular Subhalo at a particular snapshot; I make the tree of this Subhalo. I understand the linear tree, but I don't know how to interpret the 3D Tree:

-colors: indicates the velocity? which velocity? peculiar velocity, dispersion velocity or ...?

-dimension of the spheres: is it related to the solar mass of the subhalo, like for the linear tree?

-positions in the volume of the simulation : is it an overlapping of the position of every progenitor subhalo at every z?

Thanks for helping me, Flaminia

Hi Flaminia,

This is mainly meant as a qualitative tool - for any analysis, I would make sure to look at the actual values of the tree data. To answer your questions:

• You're right, color encodes velocity - the 3D velocity magnitude of the motion of the halo, over a range of ~150 to ~250 km/s (beyond this the color saturates).
• The sphere radius scales with the total halo mass (logarithmic).
• Yes the positions give the actual, 3D positions of all the progenitor subhalos at all redshifts.

yes, i need it just for a qualitative comparison. Thanks for your help