Rotational support $\left(\rho v_{\varphi }^2/2\right)>2P_{\text{th }}$ at different time snapshots highlighting the merger of the first core disc and pseudo-disc around second core formed during the 1 M_⊙ pre-stellar core collapse. The topmost plot shows the presence of both discs, which eventually merge after the outflow is launched. The white dashed vertical line marks the radius of the rotationally supported first core disc or merged disc using the definition detailed in Sect. 3.1. The gas velocity streamlines show the infalling envelope, mixing within the discs, and the outflowing gas.