Large and Energetic Supernova Remnant Candidates Are Jet-Inflated Bubbles

Among optically selected supernova remnants in nearby galaxies a few are exceptionally large (¿ 200 pc), presumably very energetic (¿ E52 erg) and have therefore been associated with putative "hypernova" events. Here we show that the extreme cases are not due to SN explosions, but rather harbour luminous X-ray binaries (often of the ULX variety) in their centers that also emit powerful relativistic winds/jets. The jets display mechanical powers of up to some E40 erg/s that can inflate supersonically expanding, huge interstellar bubbles with diameters reaching 1 kpc. The sample includes the famous case of SS433 with its associated radio nebula W50 as well as the SNR candidate S26 in the Sculptor galaxy NGC 7793 which we recently discovered to display X-ray/optical/radio hot spots and jet-inflated lobes around a central (micro-)quasar strikingly resembling a scaled-down version of a FRII-type radio galaxy