Surface density of solids in the x–y (orbital) plane, shown after self-gravity has been turned on and dense clumps have collapsed. From left to right, the panels depict runs with ﹩\tau =0.006﹩, ﹩\tau =0.3﹩, and ﹩\tau =2﹩, at times ﹩105.4{{\rm{\Omega }}}^{-1}﹩, ﹩7.6{{\rm{\Omega }}}^{-1}﹩, and ﹩8.8{{\rm{\Omega }}}^{-1}﹩ after self-gravity has been switched on, respectively. White circles depict the Hill spheres for a subset of the identified planetesimals. Both the solid surface density structure and the initial positions of planetesimals become more axisymmetric at lower values of the stopping time.