Scientists used NASA's Hubble Space Telescope to solve the mystery of how brilliant quasars are born.
The research team discovered quasars, which are the brightest objects in the universe, are created when galaxies crash into each other and fuel supermassive black holes, Yale University reported.
"The Hubble images confirm that the most luminous quasars in the universe result from violent mergers between galaxies, which fuels black hole growth and transforms the host galaxies," said C. Megan Urry, the Israel Munson Professor of Astronomy and Astrophysics at Yale University, and co-author of the study published online June 18 in The Astrophysical Journal. "These mergers are also the sites of future black hole mergers, which we hope will one day be visible with gravitational wave telescopes."
Quasars are as bright as the equivalent of a trillion stars, and in the past researchers have determined their brilliant light is emitted by supermassive holes at the centers of distant galaxies. This recent study demonstrates where the mysterious objects get their "fuel." Using Hubble's sensitivity at near-infrared wavelengths of light, the researchers were able to see the host galaxies through the intense light of present quasars.
"The Hubble observations are telling us that the peak of quasar activity in the early universe is driven by galaxies colliding and then merging together," said Eilat Glikman of Middlebury College in Vermont, lead author of the study and a former Yale postdoctoral researcher. "We are seeing the quasars in their teenage years, when they are growing quickly and all messed up."
The team focused on "dust reddened quasar," which are enveloped in light-dimming dust, in a number of ground-based infrared and radio sky surveys. Hubble's Wide Field Camera 3 revealed 11 of such quasars that are believed to have been formed 12 billion years ago, during the peak of star formation in the universe.
"The new images capture the dust-clearing transitional phase of the merger-driven black hole scenario," Glikman said. "The Hubble images are both beautiful and descriptive."
