Models for the Arp 220 western nucleus in 13CO J = 4–3 (orange lines) shown along with the observed line profiles at half-beam increments along the disk axis and perpendicular to the disk axis. 1 Jy/beam = 294.5 K. In this figure, any combination of parameters is allowed. An interactive figure is available.
An interactive version of this figure is available in the online journal.