Black-hole-triggered star formation in the dwarf galaxy Henize 2-10

Black-hole-driven outflows have been observed in some dwarf galaxies with active galactic nuclei 1 , and probably play a role in heating and expelling gas (thereby suppressing star formation), as they do in larger galaxies 2 . The extent to which black-hole outflows can trigger star formation in dwarf galaxies is unclear, because work in this area has previously focused on massive galaxies and the observational evidence is scarce 3 – 5 . Henize 2-10 is a dwarf starburst galaxy previously reported to have a central massive black hole 6 – 9 , although that interpretation has been disputed because some aspects of the observational evidence are also consistent with a supernova remnant 10 , 11 . At a distance of approximately 9 Mpc, it presents an opportunity to resolve the central region and to determine if there is evidence for a black-hole outflow influencing star formation. Here we report optical observations of Henize 2-10 with a linear resolution of a few parsecs. We find an approximately 150-pc-long ionized filament connecting the region of the black hole with a site of recent star formation. Spectroscopy reveals a sinusoid-like position–velocity structure that is well described by a simple precessing bipolar outflow. We conclude that this black-hole outflow triggered the star formation. Optical observations with a linear resolution of a few parsecs show that the outflow from the central black hole in the low-mass galaxy Henize 2-10 triggered a round of star formation.