At t= 0 Myr, the distribution of stars (black points) and gas (blue points) in the no-offset model (upper panels) and in the best-match model with offset (lower panels). Left-hand panels shows the ring galaxy from our perspective, whereas right-hand panels is the same ring but shown face-on (the subscript ‘rp’ denotes that these are coordinates within the plane of the ring). The offset does not significantly deform the ring from a circular shape, but does place the nucleus off-centre within the ring when viewed the plane of the ring face-on. We highlight the centre of the nucleus with a cross symbol (green). This offset enables us to see the nucleus at approximately the correct location within the ring from our perspective (see text for more details).