New research by astrophysicists has revealed the fastest ultraviolet winds ever detected near a supermassive black hole more than 10 billion light-years away.
“We’re talking wind speeds of 20 percent the speed of light, which is more than 200 million kilometers an hour. That’s equivalent to a category 77 hurricane,” says Jesse Rogerson, a Ph.D. student at York University in Canada. “And we have reason to believe that there are quasar winds that are even faster.”
Rogerson led this research as part of this Ph.D. thesis. The team of researchers included scientists at Humboldt State University, Pennsylvania State University and Erciyes University (Turkey). Their findings were published today in the Monthly Notices of the Royal Astronomical Society.
Astronomers have known about the existence of quasar winds since the late 1960s. At least one in four quasars have them. Quasars are the disks of hot gas that form around supermassive black holes at the center of massive galaxies.
“As matter spirals toward a black hole, some of it is blown away by the heat and light of the quasar. These are the winds that we are detecting,” says York University Associate Professor Patrick Hall, who is Rogerson’s supervisor.
Barely larger than the Earth’s orbit around the sun and much hotter than the sun’s surface, quasars generate so much light and heat that they (unlike the hundreds of billions of stars in galaxies that surround quasars) can be seen across the observable universe. Still, quasars remain a mystery.
“Quasars might be a phase that some, if not all, massive galaxies go through, like adolescence,” says Humboldt State Astronomy & Physics Professor Paola Rodriguez Hidalgo. “We know quasars are there, but we are not sure how they interact with the galaxies around them. That is why these extreme winds are so interesting.”
Rogerson and his team used data from a large survey of the sky known as the Sloan Digital Sky Survey to identify new outflows from quasars. After spotting about 300 examples, they selected about 100 for further exploration, collecting data with the Gemini Observatory’s twin telescopes in Hawaii and Chile.
"We not only confirmed this fastest-ever ultraviolet wind, but also discovered a new wind in the same quasar moving more slowly, at only 140 million kilometers an hour," says Hall. "We plan to keep watching this quasar to see what happens next."
Much of this research is aimed at better understanding outflows from quasars and why they happen.
“We suspect that quasars and their host galaxies form and evolve together, and these winds might be the key connecting them,“ says Rodriguez Hidalgo. “From what we know, as big galaxies form, they should be making far more stars than what we actually observe. So something—maybe these winds—stops galaxies from producing too many stars.”
This research was supported by the National Science and Engineering Research Council of Canada, Government of Ontario, The Scientific and Technological Research Council of Turkey, and the National Science Foundation.