[yt-users] question about parameter file

Hello, If load in a parameter file ( *pf = load("~/data/Enzo/DD0252/DD0252")*) and access the dictionary via *pf['Density'] *it returns a value of 2.49711e-30. I realize that if I enter *pf['mpc'] *it returns the conversion factor to go from system units to physical units. If yt keeps everything in cgs, then what conversion factor (if any) does *pf['Density'] *return? Thanks! ~ali