February 4, 2013 – Rare Flaring Black Hole With Blazing Jets: Astronomers using NASA’s Wide-field Infrared Survey Explorer (WISE) have captured rare data of a flaring black hole, revealing new details about these powerful objects and their blazing jets.
Scientists study the jets of black holes to learn more about the extreme environments around these mysterious space objects. Much has been learned about the material feeding black holes. However, key measurements of the brightest part of the jets, located at their bases, have been difficult despite decades of work. WISE is offering a new window into this missing link through its infrared observations.
Imagine what it would be like if our sun were to undergo sudden, random bursts, becoming three times brighter in a matter of hours and then fading back again. That’s the kind of fury observed in this jet. With WISE’s infrared vision, astronomers are able to zoom in on the inner regions near the base of the stellar-mass black hole‘s jet for the first time.
The black hole, called GX 339-4, lies more than 20,000 light-years away from Earth near the center of our galaxy. Its mass is at least six times greater than the sun. Like other black holes, it is an ultra-dense collection of matter, with gravity that is so great even light cannot escape. In this case, the black hole is orbited by a companion star that feeds it. Most of the material from the companion star is pulled into the black hole, but some of it is blasted away as a jet flowing at nearly the speed of light.
To see the bright flaring activity from a black hole, you need to be looking at the right place at the right time. WISE snapped sensitive infrared pictures every 11 seconds for a year, covering the whole sky, allowing it to catch this rare event.
Observing the jet’s variability was possible because of images taken of the same patch of sky over time. WISE data enabled the team to zoom in on the very compact region around the base of the jet streaming from the black hole. The size of the region is equivalent to the width of a dime seen at the distance of our sun.
The results were surprising, showing huge and erratic fluctuations in the jet activity on time scales ranging from 11 seconds to a few hours. Its radius is approximately 15,000 miles (24,140 kilometers), with dramatic changes by as large as a factor of 10 or more.
If you think of the black hole’s jet as a fire hose, then it’s as if astronomers discovered the flow is intermittent and the hose itself is varying wildly in size.
The new data also allowed astronomers to make the best measurements yet of the black hole’s magnetic field, which is 30,000 times more powerful than the one generated by Earth at its surface. Such a strong field is required for accelerating and channeling the flow of matter into a narrow jet. The WISE data are bringing astronomers closer than ever to understanding how these exotic phenomenon works.
The Master of Disaster