NASA Scientists Observe the Most Energetic 'Quasar Tsunamis' to Date

Astronomers have observed "quasar tsunamis," gigantic waves of radiation that emanate from quasars, which have the destructive power to wreak havoc on the formation of galaxies. The observations made through NASA's Hubble Space Telescope, described in a series of papers published in The Astrophysical Journal, include some of the most energetic to date and reveal these outflows contain, on average, 10 times more energy than previously thought. "No other phenomena carries more mechanical energy," principel investigator Nahum Arav of Virginia Tech in Blacksburg, Virginia, said in a statement. "Over the lifetime of 10 million years, these outflows produce a million times more energy than a gamma-ray burst." The amount of energy swept up in these outflows is of magnitudes several hundreds of times higher than the luminosity contained in the Milky Way, said Arav. Quasars are incredibly bright, very distant, and massive celestial objects that resemble stars from our Earth-bound vantage point. Typically they are galactic nuclei and at their center lies a supermassive blackhole around which a gaseous accretion disk has formed. As material falls towards the black hole, energy is released as electromagnetic radiation. According to NASA, these objects outshine their surroundings to the extent that they wash out the light from all other stars in their galaxies. They are the farthest known phenomena in the universe and despite their luminosity, can not be seen with the naked eye. The closest known quasar (Mrk 231) is thought to be 600 million light years from the Earth. Pressure from the radiation produces strong winds that rapidly expel material from the galaxy's interior and across its disk. These outflows, or "quasar tsunamis," can wreck the galaxy, sending particles of dust and gas across vast distances and preventing the formation of new stars. "How these outflows are formed is still a mystery," Arav told Newsweek. "One of the favored scenarios is that the radiation emanating from the quasar is pushing material in its environment to high speeds that we then see as outflows in the spectrum of the quasar." Arav and colleagues studied 13 such outflows, including three of the most energetic measured to date. Using Hubble's ultraviolet technology, the astronomers were able to determine the entire range of energy extending from these quasars, including the shortest wavelength range—the Extreme ultraviolet (EUV). It is in this part of the spectrum that the astronomers were able to make their findings. "These were previously only visible with much more difficult X-ray observations," Gerard Kriss of the Space Telescope Science Institute in Baltimore, Maryland, said in a statement. "Such powerful outflows may yield new insights into the link between the growth of a central supermassive black hole and the development of its entire host galaxy." The researchers believe these outflows could work as "major agents of change" and may explain cosmological phenomena such as the lack of large galaxies in the universe. "One of the most exciting findings was that the outflows on average have 10 times more energy than previously thought," said Arav. "This means that they are powerful enough to be a dominant process during the formation of the galaxy—for example, by curtailing its final size."