Matter caught in the forward and reverse shock at the heads of these features forms cocoons that surround and shape them. In models based on a paper by Donald Lynden-Bell, these features remain Poynting-flux-dominated over large distances due to “magnetic towers” that are laterally stabilized by ambient gas. SS 433 was the first known binary system to display these features, making that system the first microquasar. (10[2])The opening angle of these features (10[2])determines the shape of a namesake break in gamma ray burst afterglow light curves after which the curves dramatically steepen. The formation of these features by young stars was discovered (-5[1])by George Herbig and Guillermo Haro. (-5[1])Around (10[1])black holes, these features are sustained (-5[2])by magnetic (-5[1])fields (-5[1])generated (-5[1])in accretion disks. (10[1]-5[1])For 10 points, name these (-5[1])highly collimated ejections (10[1])of (10[1])plasma (10[2])pointing along the axis of rotation of galactic nuclei. (10[3])■END■ (10[3]0[7])