Averaging of the observations performed in the 88 GHz bandwidth. The main astronomical lines present in the bandwidth are indicated (in black) in the rest-frame frequency of the Andromeda galaxy, whose systemic velocity is around –300 km s^-1. For each line, the redshifted and blueshifted parts of the expected velocity range are indicated. The noise level achieved is 0.2 mK for a frequency binning Δν = 14 MHz. There are clear detections of HCO+(1–0) and HCN(1–0), with possible components at both sides of the systemic velocity.