2019MNRAS.489.1099D

Using a sample of 38 radio-loud galaxy mergers at z <= 0.2, we confirm the high detection rate (∼84 per cent) of H I 21-cm absorption in mergers, which is significantly higher (∼4 times) than in non-mergers. The distributions of the H I column density [N(H I)] and velocity shift of the absorption with respect to the systemic redshift of the galaxy hosting the radio source in mergers are significantly different from that in non-mergers. We investigate the connection of the nuclear H I gas with various multiwavelength properties of the mergers. While the inferred N(H I) and gas kinematics do not show strong (i.e. >=3σ level) correlation with galaxy properties, we find that the incidence and N(H I) of absorption tend to be slightly higher at smaller projected separations between the galaxy pairs and among the lower stellar mass-radio galaxies. The incidence, N(H I) and line width of H I absorption increase from the pre-merger to the post-merger stages. The 100 per cent detection rate in post-mergers indicates that the neutral gas in the circumnuclear regions survives the coalescence period and is not yet quenched by the nuclear radio activity.