As in Fig. 2, but at higher redshift (z > 0.548). Top-left panel: stacked spectrum of the bin 10.5 ≤ log M_∗/M_⊙ < 10.75, 0.548 ≤ z < 0.632, stellar template representing a 1.4-Gyr-old SSP with Z = 0.08 and E(B − V) = 0.2; top-right panel: 10.75 < log M_∗/M_⊙ ≤ 11, 0.632 ≤ z < 0.716, 1.4-Gyr-old SSP with Z = 0.2 and E(B − V) = 0.2; bottom-left panel: 10.75 ≤ log M_∗/M_⊙ < 11, 0.716 ≤ z < 0.8, 1.4-Gyr-old SSP with Z = 0.08 and E(B − V) = 0.2; bottom-right panel: 11 ≤ log M_∗/M_⊙ < 11.25, 0.8 ≤ z < 0.884, 1.4-Gyr-old SSP with Z = 0.2 and E(B − V) = 0.2. The stacked spectra before stellar continuum subtraction and the stellar templates have been shifted up by arbitrary quantities for clarity.