A black hole's quasar is seen jetting out a galaxy

Which existed first — galaxies or the supermassive black holes at their centers? European Southern Observatory (ESO) astronomers have observed evidence that black holes precede, give birth to and merge with their host galaxies.

A team of ESO astronomers have been observing a strange quasar, known as HE0450-2958, 5 billion light-years from us, that seemed to be the only one lacking a host galaxy. A quasar is widely theorized to be a compact, energetic region of a galaxy's central supermassive black hole. To determine if HEO450-2958's galaxy was lurking behind dust clouds, the team observed the quasar through a mid-infrared instrument on the Very Large Telescope (VLT), because dust clouds glow brightly at those wavelengths and would stand out vividly. The VLT observations showed no dust clouds or stars near the quasar and black hole at all. But a neighboring galaxy, that had been thought to be unrelated, was shown to be churning out about 350 stars per year, 100 times more than most galaxies in the Milky Way's local group produce. HEO450-2958 had already been observed jetting highly energetic particles towards its companion, amid streams of gas. Now the team theorizes that the quasar is generating a new host galaxy for itself by inducing the rapid star formation. The latest extensive observations of HEO450-2958 by the ESO team have suggested a new scenario, in which galaxies evolve from clouds of gas hit by energetic jets emerging from quasars within black holes. Papers by team leaders David Elbaz (Service d’Astrophysique, CEA Saclay, France) and Knud Jahnke (Max Planck Institute for Astronomy, Heidelberg, Germany), present these ideas in the journal Astronomy & Astrophysics: “Quasar induced galaxy formation: a new paradigm?” by Elbaz et al., and in the Astrophysical Journal “The QSO HE0450-2958: Scantily dressed or heavily robed? A normal quasar as part of an unusual ULIRG” by Jahnke et al. Elbaz explained, "Although the quasar is still ‘naked’, it will eventually be ‘dressed’ when it merges with its star-rich companion. It will then finally reside inside a host galaxy like all other quasars.” Jahnke added that searching for similar objects and processes in other systems is a natural next step. The ESO reports that future instruments, such as the Atacama Large Millimeter/submillimeter Array, the NASA/ESA/CSA James Webb Space Telescope and the European Extremely Large Telescope, capable of observing celestial objects in the far distant universe, will allow Jahnke's and Elbaz's research to continue.