Sky distribution of galaxies in SCl A2142. The red symbols show galaxies with old stellar populations (D_n(4000)≥1.55), and the blue symbols denote galaxies with young stellar populations (D_n(4000)< 1.55). Filled circles denote galaxies in rich groups with at least ten member galaxies. The crosses denote galaxies in poor groups with less than ten galaxies. The green triangles show recently quenched galaxies (RQ) with D_n(4000)≤1.55 and star formation rate logSFR < −0.5. Orange stars indicate the positions of AGNs (see text for definitions). The red-orange circle shows a projected radius of about 8 h⁻¹ Mpc. The dashed line shows the supercluster axis.