Surface number density distribution around our early-type galaxies. The bin size is 0.01 dex. We divided these galaxies into five environments in this study (colored regions): (1) 0 ≤ Σ₁₀ < 3, (2) 3 ≤ Σ₁₀ < 7, (3) 7 ≤ Σ₁₀ < 20, (4) 20 ≤ Σ₁₀ < 70, and (5) Σ₁₀ ≥ 70, where the unit of surface galaxy density is Mpc⁻². The number of galaxies in each environment is 4955, 33,521, 27,025, 6922, and 693, respectively. The boundaries correspond to −1.3σ, −0.1σ, 1.5σ, and 3.3σ, respectively.