(a) and (b): Variation in gas surface density (Σ) and the velocity component along a defined slit (u_∥) for model R801 with c_s = 10 km s⁻¹. (c) and (d) Same figures for model R991. We find that if a high surface density is initially set at the center (R991), it persists throughout the simulation; without it (R801), the central density remains low, lower than that of its surroundings, as in the case with the full potential.