Cosmic Smash: Twin Black Holes Ignite Space-Time Ripples

Most Massive Merger Ever Detected Challenges Astrophysical Models

Scientists have detected the most powerful black hole merger on record, an event occurring 10 billion light-years away that sent gravitational waves rippling across the universe. The collision involved two colossal black holes, each over 100 times the sun’s mass, forcing a re-evaluation of how such behemoths form.

A Universe Shakes

The cataclysmic event, recorded on November 23, 2023, by the Laser Interferometer Gravitational-wave Observatory (Ligo) detectors in the United States, stretched and squeezed space-time by an infinitesimal amount. This faint signal, thousands of times smaller than a proton’s width, captured the final moments as the two black holes merged into a single, more massive entity.

What are gravitational waves? They’re ripples in spacetime caused by massive cosmic events, like the merger of black holes or neutron stars. pic.twitter.com/JpT0g2bL5G

— NASA (@NASA) February 14, 2024

Professor **Mark Hannam**, head of the Gravity Exploration Institute at Cardiff University, described the phenomenon. These are the most violent events we can observe in the universe, but when the signals reach Earth, they are the weakest phenomena we can measure. By the time these ripples wash up on Earth they are tiny.

Unforeseen Giants

The colliding black holes were precisely measured at 103 and 137 times the mass of our sun. They were also observed spinning at nearly 400,000 times Earth’s rotational speed, pushing the boundaries of theoretical limits. This mass range is particularly perplexing for scientists.

These are the highest masses of black holes we’ve confidently measured with gravitational waves. And they’re strange, because they are slap bang in the range of masses where, because of all kinds of weird things that happen, we don’t expect black holes to form. explained **Hannam**, who is part of the Ligo scientific collaboration.

A New Cosmic Theory?

Typically, black holes originate from the collapse of massive stars. However, the unusual mass and spin of these merging black holes suggest a different origin. Ligo scientists hypothesize that these objects might be the result of prior black hole mergers themselves.

We’ve seen hints of this before, but this is the most extreme example where that’s probably what’s happening. **Hannam** noted.

This latest detection has surpassed previous records, with the newly formed black hole estimated to be up to 265 times the mass of the sun. For comparison, the most massive merger previously identified produced a black hole about 140 solar masses. The findings are set to be presented at the GR-Amaldi meeting in Glasgow.

The ability to detect gravitational waves, a field that gained traction in the 1990s, has revolutionized astronomy. Unlike electromagnetic radiation, gravitational waves offer a unique window into cosmic events that were previously invisible.

Looking ahead, planned detector upgrades are expected to significantly enhance our understanding of the universe’s black hole population. The detectors we have planned for the next 10 to 15 years will be able to see all the black hole mergers in the universe, and maybe some surprises we didn’t expect. **Hannam** concluded.