collimated

1. (physics, of a light beam) Composed of rays that are parallel, thus having a wavefront that is planar.Examples: "Low-mass objects have much more collimated flows than high mass sources."; "2008 May, A. M. Soderberg, et al., An extremely luminous X-ray outburst at the birth of a supernova, Accepted draft, page 3, Wolf-Rayet stars are also argued⁹ to give rise to gamma-ray bursts, a related but rare class of explosions characterized by highly-collimated relativistic jets."; "Although the most collimated outflows look very much jet-like at the highest velocities, their behavior is much more classical at lower speeds."