A collaborative effort between scholars at the Heidelberg Institute for Theoretical Studies (HITS) and Oxford University has discovered that certain black holes emit unique tones during their convergence, irrespective of their beginnings. These consistent tonal patterns, also known as chirp masses, might offer fresh perspectives into the birth and progression of black holes and the cataclysmic bursts responsible for their creation.
Black holes represent the residual cores of gigantic stars succumbing to their gravitational pull. When a pair of these voids revolve around each other and ultimately fuse, they discharge undulations in the fabric of space called gravitational waves. The initial detection of these oscillations occurred in 2015 through the instruments of the LIGO and Virgo facilities, validating a proposition made by Albert Einstein over a hundred years prior and leading to the 2017 Nobel Prize in Physics. As these voids draw nearer in their dance, the gravitational wave’s pitch escalates, emitting a distinct chirp resonance detectable on our planet. Studying these resonances allows researchers to compute the chirp mass, an amalgamation of the masses of the involved black holes.
Previously, there was an assumption that the chirp mass could fluctuate based on the specific attributes of the black holes. Yet, the models crafted by the HITS group indicate the presence of standard black hole sizes that yield consistent chirp masses. “The recognition of these constant chirp masses provides not just a glimpse into the creation of black holes,” remarks Fabian Schneider, the lead researcher at HITS, “but also gives clues about the particular stars undergoing supernova explosions.” This might pave the way to unravel some uncertainties about the supernova processes, the intricate atomic and celestial dynamics at play, and the rapid expansion of the cosmos.
What removing the envelope reveals about the birth of black holes
Unlocking the mysteries of universal chirp masses is closely tied to the process of envelope removal that happens in twin-star systems. Here, the two stars circle each other and share mass. This event influences the stars’ ultimate destiny, making it more probable that they’ll either detonate in supernovae or transform into black holes. The HITS group discovered that stars without their envelopes create black holes that are either under 9 or over 16 times the sun’s mass, but rarely anything in between. This suggests that the fusion of black holes of these typical masses will result in universal chirp masses close to 8 and 14 times the sun’s mass. “Identifiable patterns in the spread of black-hole and chirp masses provide crucial insights into the birth process of these entities,” mentions Philipp Podsiadlowski of Oxford University, co-author of the paper and presently Klaus Tschira visiting professor at HITS.
Gravitational waves might unravel the enigmas of supernovae
The team also observed an apparent gap in the detected chirp masses when two black holes combine, and an excessive presence right at the universal figures forecasted by their simulations. “Given that the count of identified black hole fusions remains modest, it’s uncertain whether this pattern in the findings is merely a statistical anomaly”, remarks Fabian Schneider. The group is optimistic that upcoming gravitational-wave detections will validate their forecasts and provide deeper insights into the characteristic resonances of black hole unions.