Recent findings from NASA's Imaging X-ray Polarimetry Explorer (IXPE) have shed light on the structure of black hole coronae, revealing that these superheated regions extend in the same direction as their accretion disks. This challenges the previous notion that coronae hover above the disks like lampposts.
Black holes, known for their intense gravitational forces that prevent light from escaping, are often surrounded by accretion disks of swirling gas and feature relativistic jets. The temperature of a black hole's corona can reach billions of degrees, significantly higher than the Sun's corona, which burns at approximately 1.8 million degrees Fahrenheit.
The IXPE mission studied 12 black holes, including Cygnus X-1 and Cygnus X-3, as well as supermassive black holes in galaxies such as NGC 1068 and NGC 4151. The data indicated that despite the vast differences in mass between stellar-mass and supermassive black holes, their accretion disks share similar structures.
Lynne Saade, a postdoctoral researcher at NASA's Marshall Space Flight Center and lead author of the study, emphasized the significance of X-ray polarization in understanding black hole accretion geometry. The findings suggest that the accretion mechanisms function similarly across different types of black holes, with stellar-mass black holes pulling mass from companion stars while supermassive black holes consume their surroundings.
Philip Kaaret, principal investigator for the IXPE mission, expressed optimism about future studies revealing deeper insights into black hole accretion processes. Saade noted that IXPE provides a unique opportunity for X-ray astronomy to uncover new findings about black holes.