The light from a black hole has revealed more about the way these objects feed.
A corona forms around the outside of the event horizon. The material from the corona is punched out into space at speeds close to that of light in a vacuum.
It resolves a long open question in black hole science.
It sounds logical, but there has been a debate for twenty years about whether the corona and the jet were the same thing.
The jet follows from the corona after they arise one after the other.
The black hole in question is located about 36,000 light-years away from the Sun. This is a normal star, not a microquasar, because it is a stellar mass black hole locked in a close system with another object and feeding off it.
The black hole takes material from the star and forms a disk around it.
It is the same thing we see in quasars, which contain a super massive black hole millions to billions of times the mass of the Sun.
The black hole GRS 1915+105 is 12 times the mass of the Sun and is one of the most massive stellar mass black holes.
The process creates a lot of light from the heating of the disk and the environment around the black hole. The corona is between the inner edge of the accretion disk and the event horizon.
This region of hot electrons is thought to be powered by the black hole's magnetic field, which acts like a synchrotron to accelerate the electrons to such high energies that they shine brightly in X-ray wavelengths.
There are jets after that. These are thought to be material accelerated along magnetic field lines outside of the black hole's event horizon to the polar regions, where they are launched into space at speed, emitting light in radio wavelengths.
This is what scientists think. It is difficult to understand the processes that take place in the space around black holes.
They wanted to learn more about how the jets are launched. Between 1996 and 2012 they collected X-ray and radio data on the microquasar.
410 simultaneous X-ray and radio observations of GRS 1915+105 was their final sample. They could see changes in the light at the same time. They found that when the X-ray light is strong, radio is weak, and that the jets are strongest when the corona is small.
This suggests that the energy that powers the microquasar system can be directed to either the X-ray corona or the jet. It seems that the corona turns into the jet in GRS 1915+105, according to models added to by the researchers.
It was a challenge to show the sequential nature of the data.
The team will try and explain some of their observations. They found that the X-ray corona is brighter than can be accounted for by temperature alone. Something else might be at play. The team believes that the magnetic field is to blame.
Magnetic fields can become tangled and chaotic because of the differential rotation of the black hole and accretion disk. The team theorizes that when the magnetic field is chaotic, material can escape, and thus the jets are launched.
This process should scale with black hole mass to help us understand how massive quasars behave.
In principle, the researchers write, the same energy flow should happen in black holes in the same way that it happens in jets and coronas.
Nature Astronomy has published the research.
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