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Some 20,000 light years away, a black hole named GX 339-4 has produced one of the most exciting visible events possible – a massive flare. This searing jet is an extraordinary occurrence and astronomers using NASA’s Wide-field Infrared Survey Explorer (WISE) were able to capture elusive data to further refine their studies of the extreme environments surrounding black holes.
Over the last several decades we’ve learned a lot about these incredible phenomenon, but there’s always room for more. By studying the accretion disk, we know what feeds them and we’ve even seen jet activity through studies using X-rays, gamma rays and radio waves. However, until now, science has never gotten a clear look at the base of jet activity… and it’s exciting more than just the material around it!
“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 we observed in this jet,” said Poshak Gandhi, a scientist with the Japan Aerospace Exploration Agency (JAXA). He is lead author of a new study on the results appearing in the Astrophysical Journal Letters. “With WISE’s infrared vision, we were able to zoom in on the inner regions near the base of the stellar-mass black hole’s jet for the first time and the physics of jets in action.”
GX 339-4 isn’t particularly unique. It’s about six times solar mass and astronomers have been studying its companion star as the material is being pulled into it. But it’s what’s escaping at nearly the speed of light that’s making researchers sit up and take notice.
“To see bright flaring activity from a black hole you need to be looking at the right place at the right time,” said Peter Eisenhardt, the project scientist for WISE at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “WISE snapped sensitive infrared pictures every 11 seconds for a year, covering the whole sky, allowing it to catch this rare event.”
A variable jet? It would seem so. Thanks to NEOWISE, the same area of sky was repeatedly photographed – allowing the team to home in on the elusive base area. Just how elusive? Try to imagine an area the size of your thumbnail seen at the distance of the Sun! Its radius is approximately 15,000 miles (24,140 kilometers) with dramatic changes by as large as a factor of 10 or more. To see an event that lasted anywhere from 11 seconds to a few hours might seem incredulous, but these immense variations blasted through in infra-red.
“If you think of the black hole’s jet as a firehose, then it’s as if we’ve discovered the flow is intermittent and the hose itself is varying wildly in size,” Poshak said.
But that’s not all the data. This new information has given science the best to-date values on black hole magnetic fields – ones that are 30,000 times more powerful than those that belong to planet Earth. It’s these fields that channels the flow of energy and accelerates it. But, there’s still that curiosity factor of why it varies, isn’t there?
We’ll keep asking questions. After all… Science is WISE.
Original Story Source: NASA News.
Hm. A paper would be nice for this. This could also give us a lot hints for their greater cousins: Jets of supermassive black holes.
I wonder, if we will ever see a jet of a stellar size black hole as a blazar, that is the jet pointing directly at us. I would really like to see such a spectrum, to compare it to actual blazars. What are the odds?
Ask and you shall receive: A variable mid-infrared synchrotron break associated with the compact jet in GX 339-4 [PDF].
Thanks. That’s why we need you: Not only do you correct the language, you also provide us with papers and links. Nice!
Did I say it? Thanks!
You’re welcome!
In an undergraduate astrophysics course the solar model is worked out. In this case the star was modeled as static. Of course we know the sun and other stars are not static, but rather have complex behavior that is not only just periodic, but chaotic as well. These variations are similar, and illustrate that the “101 model” of a stationary accretion disk is an approximation. Factors such as variations in energy output from the star, or a high eccentricity in the mutual orbit of the black hole and star and so forth can set up variations.
LC
Of course. That is what a black hole does, after all:
– What did the Super-Massive Black Hole say to the Tiddly Widdly Winkie Star?
– …
– Come closer, there’s always room for more!
I am surprised to hear of a black hole of only 6 solar masses. Surely a supernova of that size would merely blow off its outer layers and leave behind a neutron star, like the crab nebula.
I know that my following suggestion does not explain the size anomoly but is it possible that this supernova did exactly that, i.e. create a neutron star, but that since that event, large amounts of additional material have been accreted, perhaps from its companion star, such that the smallest mass threshold for a black hole has been achieved and that the neutron star then collapsed further.
Any thoughts on the mass dilemma?