NASA IXPE Detects Unusual ‘Heartbeat Black Hole’ Activity

Key Takeaways

1. Astronomers used NASA’s IXPE to study the Heartbeat Black Hole, finding a polarization degree of 9.1%, which is higher than expected.
2. The corona is a hot X-ray-emitting region near the black hole, close to the accretion disk that pulls in matter from nearby stars.
3. A 9.1% polarization suggests that the black hole’s corona is ideally shaped and viewed edge-on, but the exact angle remains unclear.
4. Researchers proposed a model where X-rays pass through a wind of matter from the accretion disk, leading to increased alignment through Compton scattering.
5. An alternative explanation involves plasma moving at high speeds within the corona, potentially increasing the observed polarization due to relativistic effects.

Back in April, astronomers utilized NASA’s Imaging X-ray Polarimetry Explorer (IXPE) to investigate the Heartbeat Black Hole. The data revealed a polarization degree of 9.1%, significantly exceeding initial expectations. This finding indicates that the X-ray vibrations emitted from the black hole are highly aligned.

Understanding the Corona

The corona represents an intensely hot X-ray-emitting area located near the center of a black hole, situated close to the innermost section of the accretion disk. This accretion disk is a flattened, rotating formation typically composed of matter being drawn from nearby stars.

Implications of High Polarization

A polarization degree reaching 9.1% implies that the corona of the black hole is ideally shaped and seen from an edge-on perspective; however, the scientists were unable to directly assess the viewing angle due to the faintness of the stellar companion.

To clarify this unusual phenomenon, the astronomers proposed a model that involved a wind of matter being expelled from the accretion disk. In this scenario, the X-rays emitted from the corona travel through the wind, experience Compton scattering, and become more aligned as a result.

Alternative Explanations

Another possibility is that the plasma within the corona might be moving outward at speeds up to 20% of the speed of light. If this is the case, relativistic effects could cause the polarization to appear even higher than it actually is. Future research will investigate additional models to further unravel this enigma, and deciphering it will enhance our current knowledge of astronomy.

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