MIT Discovers 18 New Black Holes Ripping Apart Stars in Cosmic Feeding Frenzy
In a groundbreaking discovery, a team of researchers from the Massachusetts Institute of Technology (MIT) has identified 18 new instances of black holes tearing apart stars and consuming their remains. This finding has more than doubled the number of Tidal Disruption Events (TDEs) observed in the local universe, shedding light on the prevalence of these cosmic phenomena.
TDEs occur when a star comes too close to a black hole, resulting in the star being stretched vertically and squashed horizontally due to the immense tidal forces generated by the black hole’s gravitational influence. This process, known as “spaghettification,” leads to the formation of a flattened disk of material around the black hole. Some of this material is accreted by the black hole, while the rest is expelled as near-light speed jets.
Previously, astronomers believed that TDEs only occurred in galaxies that had recently undergone intense starbursts. However, this new research suggests that TDEs can happen across a wider range of galaxies, providing insights into the extreme physics surrounding these events.
Erin Kara, an assistant professor of physics at MIT and a member of the research team, expressed her excitement about the findings, stating, “People were coming up with very exotic solutions to these puzzles, and now we’ve come to the point where we can resolve all of them.”
The hunt for TDEs began when the MIT team discovered the closest TDE ever observed from Earth. This discovery led them to develop a new method for detecting actively feeding black holes using infrared light and an algorithm that identifies transient bursts of radiation. By analyzing data collected by NASA’s Wide-field Infrared Survey Explorer (NEOWISE), the researchers were able to identify infrared bursts from about 1,000 galaxies within a distance of 600 million light-years from Earth.
To confirm that these signals were indeed TDEs, the team examined the galaxies in detail, ruling out other violent events such as supernova explosions or the feeding of supermassive black holes. This meticulous process ultimately led to the identification of 18 legitimate TDE signals caused by black holes tearing apart stars.
One surprising finding from the research is that TDEs occur across a wide range of galaxies, including those filled with thick clouds of dust. Megan Masterson, a graduate student at MIT’s Kavli Institute for Astrophysics and Space Research and lead author of the study, explained, “If you looked up in the sky and saw a bunch of galaxies, the TDEs would occur representatively in all of them.”
This discovery also helps explain why TDEs were previously thought to be restricted to post-starburst galaxies. These galaxies, which have recently ceased star formation, lack thick gas and dust due to the depletion of materials during the starburst phase. In contrast, other galaxies still possess abundant gas and dust, which can absorb or block optical and X-ray light. However, infrared observations can penetrate through the dust, making them crucial for detecting TDEs in dusty galaxies.
The findings from this research also shed light on the energy emitted by TDEs. The team suggests that the energy deficit observed in these events is due to dust absorbing optical and X-ray emissions, as well as extreme ultraviolet radiation from TDEs.
By adding the 18 newly discovered TDEs to previously observed events, the MIT team estimates that galaxies experience a TDE approximately once every 50,000 years, aligning with theoretical predictions.
“This gives us confidence that we don’t need all this exotic physics to explain what we’re seeing,” concluded Kara. “And we have a better handle on the mechanics behind how a star gets ripped apart and gobbled up by a black hole. We’re understanding these systems better.”
The team’s research, published in the Astrophysical Journal, marks a significant step forward in our understanding of TDEs and their occurrence across different types of galaxies. With this newfound knowledge, astronomers can refine their estimates of TDE rates across the universe, bringing them closer to theoretical predictions.