Scientists have recently unraveled a fascinating mystery behind a remarkable black hole merger observed 7 billion light-years away. This event, detected as ripples in space-time called gravitational waves, raised eyebrows because it involved two unusually massive black holes—one weighing 100 times and the other 140 times more than our Sun. These giant black holes shouldn’t exist based on current theories of their formation from dying stars.
Typically, when massive stars explode in supernovae, the expected outcome doesn’t include black holes that massive. As Ore Gottlieb, an astrophysicist at the Flatiron Institute, put it, stars that die in “pair-instability supernovae” leave nothing behind. Therefore, finding black holes in this “mass gap” was particularly puzzling.
The groundbreaking work of the Flatiron Institute’s Center for Computational Astrophysics (CCA) employed simulations to investigate this mystery. They focused on how the progenitor stars evolved before their supernova deaths. A key element overlooked in past studies was the influence of magnetic fields, which turned out to be crucial to understanding how these massive black holes formed.
Gottlieb explained that prior approaches ignored these fields, effectively taking a shortcut in their analysis. However, when they included magnetic fields in their simulations, everything changed.
The team’s findings indicated that a rapidly spinning progenitor star could lose more mass than previously thought during its collapse. In their simulations, they found that instead of being fully consumed by the forming black hole, leftover stellar material could create a rotating disk around it. This disk might accelerate the black hole’s spin and potentially even eject some material at nearly the speed of light.
This research offers a fresh perspective not only on how these black holes might exist but also suggests a potential link between a black hole’s mass and its rotational speed. Stronger magnetic fields could lead to lighter, slower-spinning black holes, while weaker fields might create more massive, faster-spinning ones.
Recent studies indicate that close to half of the matter from a collapsing star can be expelled if magnetic fields are strong enough. This could explain the existence of black holes within the mass gap while providing a new avenue for astronomers to explore.
Moreover, if a black hole forms in such a tumultuous process, it could be associated with bursts of detectable gamma rays. This could pave the way for future observations that would enhance our understanding of black holes and their formation.
The implications of this study extend beyond theoretical musings; they might help process data from gravitational wave detectors like LIGO and Virgo. These findings underscore the importance of incorporating new variables into astrophysical models, offering a clearer picture of the complexities of our universe.
This research was published in The Astrophysical Journal Letters, making it a significant milestone in our ongoing quest to comprehend the enigmatic nature of black holes and the cosmic events surrounding their formation.
For more details, you can read the original research here.
