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NASA and ESA measure strength of wind from a supermassive black hole

Black Hole

We tend to think of black holes pulling things in rather than blowing them out, but the tremendous space-warping forces at play in the vicinity of the largest black holes can do weird things. For the first time scientists have been able to measure the speed of a black hole’s “wind” and it’s really, really fast. So fast, in fact, that supermassive black holes like the one at the center of the Milky Way could limit star formation within the galaxy.

These new measurements were made with NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and the ESA’s XMM-Newton telescope. These are both orbital instruments designed to observe the universe in the X-ray portion of the electromagnetic spectrum. Black holes are a powerful source of X-ray radiation, so these were the perfect instruments for observing the wind coming off of them.
Of course, we’re not really talking about wind like we have on Earth. In astronomical lingo, wind usually refers to currents of charged particles that are emanated from an object. You’ve probably heard of solar wind before — well, this is the same thing but for black holes. These particles aren’t coming from the black hole itself (nothing escapes the event horizon, as far as we know), but matter that falls toward the center can actually be accelerated and shot off into space rather than being sucked in.
Astronomers already knew that the winds coming from a black hole could reach amazing speeds, as much as one-third the speed of light (nearly 100 million meters per second). To better characterize this phenomenon, NASA and the ESA observed a distant and extremely active black hole called PDS 456. These objects are sometimes called quasars, and this one blasts out more energy as “wind” than one-trillion stars like the sun.
The new data from NuSTAR and XMM-Newton tell us that the wind isn’t emitted like a beam in one direction, but that it likely flows outward in all directions. These instruments were able to make five separate observations of PDS 456 (which is about 2 billion light years distant) in 2013 and 2014. Data from the lower-energy XMM-Newton detected iron atoms being blasted out with the wind directly in front of the black hole. When data from the high-power NuSTAR array was added in, astronomers confirmed iron being carried by the winds in other directions, indicating the wind pushes in all directions.
So what does this mean for galaxies and their black hole hubs? The bulge in the center of a galaxy usually points to a more massive black hole. These objects are pushing out more wind throughout the galaxy, and that’s likely to suppress the formation of new stars. It’s yet another way the fate of a galaxy is linked to its supermassive black hole. This data also helps astronomers reconstruct conditions in the early universe, when large black holes were more common, and their winds may have shaped the universe we know today.

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