Surprisingly Strong Magnetic Fields Match Supermassive Black Hole's Relentless Pull
Supermassive black holes churn in the centers of galaxies, powering the system. Now, scientists have learned a bit more about these black holes and have found that magnetic fields play an impressive role in the systems' dynamics; in fact, it turns out that the magnetic field strength actually matches the force produced by a black hole's powerful gravitational pull.
Researchers have previously created computational models of black holes that have included magnetic fields. These models suggested a black hole could sustain a magnetic field that was as strong as its gravity yet until now, there's been no observational evidence to support these models.
Now, that's changed. The scientists found evidence from jets of gas that shoot away from supermassive black holes. Formed by magnetic fields, these jets produce a radio emission that the researchers then used to measure the magnetic field strength near the black hole itself.
"This paper for the first time systematically measures the strength of magnetic fields near black holes," said Alexander Tchekhovskoy, one of the researchers, in a news release. "This is important because we had no idea, and now we have evidence from not just one, not just two, but from 76 black holes."
In fact, the researchers found not only that the measured magnetic fields can be as strong as a black hole's gravity, but that they are also comparable in strength to those produced inside MRI machines found in hospitals, which are roughly 10,000 times greater than the field of Earth itself.
"The magnetic fields are strong enough to dramatically alter how gas falls into black holes and how gas produces outflows that we do observe, much stronger than what has usually been assumed," said Tchekhovskoy in a news release. "We need to go back and look at our models once again."
The findings are published in the journal Nature.