Extended Data Fig. 3: [O ii] spatial profiles.

Profiles are averaged and then plotted versus distance from the galaxy nucleus along circular radii (black); the short axis of the nebula, or east-to-west axis (blue); and the long axis of the nebula, or north-to-south axis (purple). The averages are taken in directions perpendicular to these: in azimuth around the nucleus; along the long axis; and along the short axis, respectively. The short and long axis profiles are shifted upward in flux so that the three profiles match in the lowest distance bin. Errors are standard errors of the mean. Plotted as dashed lines are the stellar half-light radius (orange), the [O ii] half-light radius within 50 kpc (black), and the [O ii] maximum radius along the short and long axes (blue and purple).