Understanding these winds is crucial to understanding how galaxies, including our own, grow.
- Dr Michael Parker
Outflowing gas is a common feature of the supermassive black holes that reside at the centre of large galaxies. Often millions of times more massive than the Sun, these black holes feed off the surrounding gas that swirls around them. Space telescopes observe this as a bright light from the innermost part of the disc around the black hole.
Occasionally the black holes consume too much gas and release an ultra-fast wind. These winds are an important characteristic to study because they could have a strong influence on regulating the growth of the host galaxy by clearing the surrounding gas away and therefore suppressing the birth of stars.
Using ESA’s XMM-Newton and NASA’s NuStar telescopes, scientists have now made the most detailed observation yet of such an outflow. The winds recorded from the black hole reach 71,000 km/s – a quarter of the speed of light – putting it in the top 5% of fastest known black hole winds.
XMM-Newton focused on the black hole for 17 consecutive days, revealing the extremely variable nature of the winds.
“We often only have one observation of a particular object, then several months or even years later we observe it again and see if there’s been a change,” says Dr Michael Parker of the Institute of Astronomy at the University of Cambridge, UK, lead author on a paper published in Nature this week which describes the discovery.
“Thanks to this long observation campaign, we observed changes in the winds on a timescale of less than an hour for the first time.”
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Image: Artist's impression of the winds emanating from the supermassive black hole
Credit: European Space Agency (ESA)
Reproduced courtesy of the University of Cambridge
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