B/T flux ratio distributions shown for bright and faint galaxies. Top panel: B/T flux ratio distributions of the inclusive unbiased double-peak sample (UDP_I) divided into two Lyα luminosity bins with the same number of objects (53 and 52). The faint subsample (L_Lyα < 3.7 × 10⁴¹ erg s⁻¹) is in black and the bright one (L_Lyα > 3.7 × 10⁴¹ erg s⁻¹) is in grey. Bottom panel: B/T flux ratio distributions of the restrictive unbiased double-peak sample (UDP_R) divided into two Lyα luminosity bins with the same number of objects (33 and 33). The faint subsample (L_Lyα < 3.9 × 10⁴¹ erg s⁻¹) is in stepped orange and the bright one (L_Lyα > 3.9 × 10⁴¹ erg s⁻¹) is in orange. B/T = 0.5 is represented by a black dash-dotted line in both panels.