Astronomers have found normally mild-mannered LINER galaxies, left, in the process of transforming into voracious quasars as seen in the artist’s rendering at right. Credit: ESA/Hubble, NASA and S. Smartt (Queen’s University Belfast (left), NASA/JPL-Caltech (right)
Galaxies are such enormous structures that major changes occur over extreme timescales. But astronomers have identified six previously mild-mannered galaxies that suddenly transformed into voracious quasars, erupting in feeding frenzies powered by supermassive black holes.
“It’s surprising that any galaxy can change its look on human time scales,” said Sara Frederick, a graduate student at the University of Maryland and lead author of a paper in The Astrophysical Journal. “These changes are taking place much more quickly than we can explain with current quasar theory.
“It will take some work to understand what can disrupt a galaxy’s accretion structure and cause these changes on such short order. The forces at play must be very extreme and very dramatic.”
Galaxies come in a variety of shapes, size and brightness, ranging from low-key “ordinary” star swarms to super-luminous active galaxies, or quasars, that host supermassive black holes at their cores and emit torrents of radiation as they consume surrounding gas and dust.
In between those two ...