December 8, 2018
Wind From A Distant Black Hole Spotted 228,000 Light-Years Away From Its Galaxy

Astronomers studying the universe's first light — the light from the first stars, which ignited nearly 14 billion years ago, according to the European Southern Observatory (ESO) — have made an unexpected discovery.

While scouring the distant cosmos with the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile, the scientists came across a streak of thermal wind spewed from a far-flung black hole, which had traveled a staggering distance from the galaxy where it originated.

Although it's not uncommon for black holes to cast material some distance away from their galaxy, reaching as far as 3,000 light-years into the cosmos, in this particular case, wind coming from the black hole was spotted no less than 228,000 light-years away from its source of origin.

This is the farthest away that black hole wind has ever been known to extend, reports Science News.

What Is Black Hole Wind?

This astonishing detection was traced back to a quasar called HE 0515-4414, a very luminous black hole located about 268 million light-years away from Earth.

As the Inquisitr previously reported, quasars are the brightest objects in the universe and consist of a supermassive black hole surrounded by an immense disk of gas.

This disk is constantly swirling around the black hole, getting heated to hundreds of million of degrees Celsius. The incredible heat, along with the black hole's magnetism, lead to the formation of turbulent winds made out of hot gas and thermal plasma, which get flung into outer space.

"Supermassive black holes at the cores of galaxies blast radiation and ultra-fast winds outward. […] These winds, which contain gases of highly ionized atoms, blow in a nearly spherical fashion, emanating in every direction," notes NASA.

Artist's rendition of black hole wind emanating from a galaxy.
Artist's rendition of black hole wind emanating from a galaxy.

"The black hole can't swallow all of that stuff. It has to blow some of it out," team leader Mark Lacy explains.

In an effort to find out how far black hole wind can travel and how much of the quasar's energy it can carry with it, Lacy and his colleagues took a good look at quasar HE 0515-4414. The team studied the quasar against the cosmic microwave background — the oldest light in the universe, which now exists only as weak microwave radiation — to observe how the wind coming from this black hole scattered the universe's oldest photons.

As ESO points out, this distortion of the cosmic microwave background is known as the Sunyaev-Zel'dovich effect. In 1999, a study published in the Monthly Notices of the Royal Astronomical Society theorized that this effect could be used to measure the energy of black hole wind and how far it extends from the galaxy. Now, for the first time ever, someone has proven that it is possible.

Illustration of the the Sunyaev-Zel'dovich effect.
ALMA (ESO/NAOJ/NRAO)/T. Kitayama (Toho University, Japan)/ESA/Hubble & NASA
Illustration of the the Sunyaev-Zel'dovich effect.

In a paper published last month on the pre-print server arXiv, the team explains that, in this particular case, the effect was "induced by the bubble of thermal plasma blown into the intergalactic medium by the quasar wind."

"We have made the first detection of such a bubble, associated with the hyperluminous quasar HE0515-4414."
According to ongoing theories, powerful black hole winds that displace a large amount of energy can be mighty enough to blow away the galaxy's star-forming gas and even to stop it in its tracks. This could explain why galaxies seem to have a limit to how much mass they can accumulate.

"Theoretical calculations suggest that if a black hole can blow away 1 or 2 percent of the total energy of a quasar in the wind, that would be enough to shut a galaxy down," states Science News.

However, in the case of HE 0515-4414, the team calculated that the wind only displaced about 0.01 percent of the quasar's total energy.

"That doesn't mean the theory is completely dead," said Lacy, who is a researcher at the National Radio Astronomy Observatory.

As he explains, the observed wind seems to have blown a large, long-lasting bubble, instead of simply streaming outward in a continuous gust. This bubble is believed to be able to outlive the quasar, lasting for millions of years, and eventually strip the galaxy of star-forming gas. This, in turn, could explain why galaxies can't grow in mass past a certain point, even in the absence of an active black hole.

"To me that's the next frontier, to find these ghost outflows hanging around quasars that might be dead," said astrophysicist Priyamvada Natarajan of Yale University, who authored the 1999 study.