Integrated opacities for f_c = 0.38 of the blue wing of the HCO⁺J = 2 ← 1 lines (−37.6 km s^-1<V_LSR< −2.6 km s^-1; V_LSR = V_HEL + 12.4 km s^-1; z = 0.88582) and of CS J = 1 ← 0 (see also Fig. 3 and Table 3). The HCO⁺ spectra were taken from IRAM Pico Veleta (30-m) and Plateau de Bure (PdBI) data published by Muller & Guélin (2008). Their calibration uncertainties are 15% and 1%, respectively. For the Effelsberg data, see Sect. 2.