Space Telescope Science
Astronomers have long wondered how the universe's largest elliptical galaxies continue making stars long after their peak years of star birth. By combining data from NASA's Hubble Space Telescope with observations from a suite of ground-based and space telescopes, two independent teams have uncovered a unique process to explain how this star birth continues. The teams found that that the galaxy's central black hole, jets, and newborn stars are all parts of a self-regulating cycle. In that cycle, jets shooting out of the galaxy's center heat a halo of surrounding gas, controlling the rate at which it cools and falls into the galaxy. The astronomers used Hubble's high resolution and ultraviolet vision to resolve brilliant knots of hot, blue stars forming along the jets from active black holes in the centers of these giant galaxies.