- read the table with the following command:
readcol,'anatoly_simulations.tbl',xx,yy,zz,vx,vy,vz,mass,radius,Vrms,Vcirc,Npart,format='D,D,D,D,D,D,D,D,D,D,D'
The "readcol" command is included in the astronomical package of IDL.
If you did not instal it, then use this table (in IDL format) and read it with the command:
restore,'anatoly_simulations.xdr',/verb
- launch: plot_anatoly,xx,yy,zz,Vcirc.
after retrieving the program: plot_anatoly.pro (IDL)
If you used the IDL table, "anatoly_simulations.xdr", then type:
plot_anatoly,cat.xx,cat.yy,cat.zz,cat.Vcirc
LARGE-SCALE STRUCTURES
This simulation of a 60 h^-1 Mpc box of universe was made by Anatoly Klypin. It represents the distribution of dark matter in the present-day universe and each point is a dark matter halo where visible galaxies are expected to be located, i.e. the distribution of dark matter haloes can be compared with the distribution of galaxies in catalogs of galaxies. The Table (ASCII) contains the x,y,z positions in Mpc, i.e. 3.0856x10^22 m, of all haloes.
The initial result of the simulation is a table of dark matter particles. For each particle, the code searched for the maximum value of the circular velocity as a function of increasing radius in concentric spheres. The circular velocity is the velocity at which a particle will stay in circular orbit around the center of the halo, i.e. Vcirc= sqrt(GM/r)= Vescape/sqrt(2). Once max(Vcirc) was found, a halo is given its mass (M) within the radius (R) of maximum Vcirc. The rms of all velocities of the Npart within R is Vrms.
The other columns of the Table give M, R(Mpc), Vrms, Vcirc, Npart in this order. A maximum radius of 150 kpc=0.15 Mpc was imposed to the code defining the dark matter haloes.
In order to visualize the simulation in a 3D plot with IDL, you can use the following commands: