Galactic jets tied to galaxy collisions
DOI: 10.1063/PT.5.028918
Nature : Black holes are at the center of most large galaxies. In some galaxies black holes are quiet, while in other, more active galaxies the black holes lie at the origin of massive jets that spew charged particles in directions perpendicular to the galactic plane. Now, Marco Chiaberge of the Space Telescope Science Institute in Baltimore, Maryland, and his colleagues offer an explanation for why only a few active galactic nuclei have jets. Examining 19 galaxies with jets, all of which are at least 7.8 billion light-years away, they found that all 19 were undergoing mergers in which two central black holes had begun orbiting each other. It is the gravitational effect of the black holes spinning around each other that is accelerating the material and ejecting it out of the merging galaxies.
