X-rays reveal superheated blob around a black hole

The Cygnus X-1 system is one of the brightest sources of x-rays in the Milky Way, consisting of a black hole called Cygnus X-1 and its giant companion, a star that packs 41 times the mass of our sun. Re-searchers recently measured the polarization of those X-rays to better understand the geometry of the superheated plasma in the Cygnus X-1 system.

Although nothing is visible beyond a black hole’s event horizon, superheated matter usually surrounds a black hole. Bee millions of degrees, matter emits X-rays that provide information about the environment they come from.

“Previous X-ray observations of black holes only measured the direction of arrival, arrival time and energy of the X-rays from hot plasma that spiraled into the black holes,” Henric Krawczynski, a physicist at Washington University in St. Louis told the paper. lead author, at a university release. “IXPE also measures their linear polarization, which contains information about how the X-rays were emitted—and whether, and where, they scatter material close to the black hole.”

Some of the data came from the Imaging X-Ray Polarimetry Explorer (IXPE) mission. IXPE is a satellite orbiting the Earth that launched in December 2021. The mission is planned for two years; except black holes, IXPE looks at X-ray sources such as neutron stars, pulsars, nebulae, and the remnants of supernovas.

The researchers combined the IXPE observations with data from NASA’s NICER and NuSTAR X-ray observatories to get a better idea of ​​the whereabouts of the plasma around Cygnus X-1. Their work is published today in the journal Science.

They found that the plasma formed a disk that is perpendicular to the jets of material shooting out on either side of the black hole. It is believed that black hole rays are formed by strong magnetic fields, which spread some of the superheated material on either side of the object in large streams of activated particles accelerated to nearly the speed of light.

As Sagittarius A*, the supermassive black hole at the center of our galaxy, has these jets, we wouldn’t be able to see them. That’s because the black hole is aimed directly at us.

The directions of the jets and the polarization of the system’s X-rays are aligned, which the study suggested team that whatever is going on in the bright area near the black hole is related to the formation of the jets.

In addition, the polarization of the X-rays the team suspects that the plane of the black hole may not be aligned with the Cygnus The aircraft of the X-1 system. Previous evidence has shown that this can happen when the black hole is forming by the violent death of his ancestor.

The explosion of material from the star’s death could make the newly formed black hole a birth shovel, making it out of sync with the surrounding objects. The small black hole in MAXI J1820+720for example, about 40 degrees is not aligned with the disk of material around it.

IXPE (and its fellow X-ray observatories) will continue to reveal new aspects of black hole formation and evolution over time, giving us a more complete picture of the diversity of these extremely dense, enigmatic objects.

More: See: The first image of our galaxy’s central black hole