Sometimes, the storms that rage in the cosmos are infinitely more powerful than anything that can come at us on Earth. Think space tsunamis.
Tsunamis on Earth are violent enough, with monster waves crashing and destroying and usually taking fatalities with them. In interstellar space, those fatalities are stars. Now NASA scientists using its Hubble Space Telescope have discovered the most powerful quasar outflows that have ever been observed, which are ripping through their galaxies — and others — much like tsunamis of hot gas.
"No other phenomena carries more mechanical energy. Over the lifetime of 10 million years, these outflows produce a million times more energy than a gamma-ray burst," explained Nahum Arav of Virginia Tech, principal investigator of a six-part study recently published in The Astrophysical Journal.
But first, just a reminder on how menacing quasars can be. These objects are basically supermassive black holes (which are also galactic centers) that devour immense amounts of matter and emit unbelievable amounts of energy. Infalling matter travels almost as fast as the speed of light, making it blaze. As matter falls into the black hole’s gaping maw, the hot gas that swirls around it emits such intense radiation that it can be a thousand times brighter than the host galaxy. This is kind of a big deal in a galaxy already shining with billions of stars.
While this already sounds like a space horror B-movie waiting to happen, what really startled Arav’s team was the gargantuan outflows of blistering gas. Intense radiation pressure creates winds that push material away from the supermassive black hole and through the galactic disc at velocities high enough to be just a small percent of the speed of light. One of the outflows was zooming through the void at 46 million miles an hour. With them, they take material that would have otherwise formed new stars if it had had the time to stay in one place long enough for clumps of gas and dust to accrete over the millions of years it takes to form a star.
"The winds are pushing hundreds of solar masses of material each year. The amount of mechanical energy that these outflows carry is up to several hundreds of times higher than the luminosity of the entire Milky Way galaxy," Arav said.
His team’s find could finally explain why such massive galaxies don’t birth the amount of stars they were previously expected to. When they put the quasar outflows observed by Hubble into simulations meant to show how galaxies evolved, that explained why stars just aren’t able to form in galaxies of this size. The Hubble data showed ghostly trails of light from the blazing gas as it swept through space. Hubble is the only spacecraft that has a specific enough range of UV sensitivity that allowed these observations to shine through, since it is able to track the entire range of quasar vomit which includes those hot ionized winds.
While other scientists have had suspicions about some mysterious force that switches off star formation in these galaxies, this is the first time that anyone has been able to reveal what that force is.
"These were previously only visible with much more difficult X-ray observations,” said Gerard Kriss of the Space Telescope Science Institute in Baltimore, Maryland, who was one of Arav’s researchers. “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."
If you could actually see this phenomenon in the night sky, it would be the most epic light show you could ever imagine. Nature really can create the most awesome special effects.