Scientists discover that jets shooting from black hole contain nickel and iron

Scientists say they found traces of nickel and iron in the powerful jets shooting out of black hole candidate 4U 1630-47, a small black hole just a few times the mass of our sun. It may help solve a scientific puzzle that has lingered for decades.

Astronomers have known for years that hyper-dense black holes shoot matter into the universe in high-speed streams known as relativistic jets. However, nobody knew exactly what type of material the jets were spewing.

"It was one of the unsolved questions about relativistic jets produced in the vicinity of black holes," said Avi Loeb, chair of the department of astronomy at Harvard University, who was not involved with the study, reported in the journal Nature. "What is their composition?"

Everyone was in agreement that the jets would contain electrons, which have a negative charge. But the jets did not have a negative charge overall. That suggested there was something else in there with a positive charge that cancelled it out.

In addition, some models of the jets suggested they were shooting lightweight electrons and positrons away from the black hole and into the universe. Others thought the jets were made of much heavier normal matter.

"Until now, it wasn't clear whether the positive charge came from positrons, the antimatter 'opposite' of electrons, or positively charged atoms," study co-author James Miller-Jones of the International Centre for Radio Astronomy Research said in a statement. "Since our results found nickel and iron in these jets, we now know that ordinary matter must be providing the positive charge."