Astrophysics: Jellyfish galaxies feeding supermassive black holes

An explanation of how supermassive black holes are fed in ‘jellyfish’ galaxies is proposed in this week’s Nature.

Most galaxies are thought to contain a supermassive black hole at their centres, but only a few are accumulating, or accreting, matter, producing highly energetic active galactic nuclei (AGN). Jellyfish galaxies are characterized by long ‘tentacles’ of gas and newly born stars that make them resemble their aquatic animal namesakes. These features are thought to be indicative of gas being stripped away owing to the motion of the galaxy through the intracluster medium (the gas that exists between galaxies in clusters of galaxies), a process known as ram-pressure stripping.

Bianca Poggianti and colleagues observe seven jellyfish galaxies and report the presence of AGN in six of these. The authors propose that the ram pressure responsible for stripping gas from these galaxies could also funnel gas towards the central supermassive black hole, triggering AGN activity.