Comparison between the evolution of planetesimals of ﹩m=2\cdot {10}^{25}\;{\rm{g}}﹩ in protoplanetary disks with with different disk density profiles normalized at 1 AU. Solid lines indicate circular orbits; dashed lines indicate eccentric orbits with an initial eccentricity of e = 0.1. Black, blue, and green lines indicate density profile ﹩{{\rm{\Sigma }}}_{{\rm{g}}}\sim {a}^{-\alpha }﹩ where α is 1, 1.5, and 2, respectively. Top left: evolution of the semimajor axis. Top right: evolution of orbital eccentricity. Note the logarithmic scale. Bottom left: evolution of semimajor axis zoomed in on the first ﹩{10}^{4}﹩ years. Bottom right: evolution of Mach number. Note the logarithmic scale.