Milky Way Gas Creates Multiple Images of Distant Quasar

Astronomers have captured a new image of a distant quasar, a luminous and active galactic nucleus. Yet this image is a bit unusual. For the first time, the researchers have taken a picture of a quasar split into multiple images by the effects of a cloud of ionized gas in our Milky Way. The findings confirm a theory that was first set forth in 1970 but until now, has not been proven.

The quasar, named 2023+355, is located nearly 3 billion light-years from Earth. In the series of images taken of the quasar, there are some dramatic and startling differences. Yet these differences aren't from the quasar itself; instead, they're caused by the radio waves from the quasar being bent as they pass through the Milky Way gas cloud.

"The event, obviously rare, gives us a new way to learn some of the properties of the turbulent gas that makes up a significant part of our galaxy," said Matt Lister, one of the researchers, in a news release. "We've never seen this type of behavior before, either among the hundreds of quasars in our own observing program or among those observed in other studies."

When the astronomers initially spied quasar 2023+335, they saw a typical structure. It had a supermassive black hole at its core which powered "jets" of material that nearly reached the speed of light. In 2009, though, its appearance changed; it looked like a line of bright, new radio-emitting spots.

The cloud of gas that caused this alteration is located nearly 5,000 light-years from Earth in the direction of the constellation Cygnus. Moving through space at about 56 kilometers per second, the cloud's size is comparable to the distance between the sun and Mercury.

The findings reveal a little bit more about these unusual, visual events. In addition, it could yield more information about both the process by which the waves are scattered and about the gas that does the scattering.

The findings are published in the journal Astronomy and Astrophysics.