2025-06-16 19:18:00
Astronomers have discovered a black hole of epic proportions, a cosmic giant weighing in at a staggering 36 billion times the mass of our sun.
- An ultramassive black hole (UMBH) has been directly measured with a mass of 36 billion solar masses.
- The black hole is located at the center of the galaxy LRG 3-757, about six billion light-years away.
- This discovery was made using gravitational lens modeling and stellar dynamics.
The discovery, led by Carlos R. Melo-Carneiro from the Institute of Physics at Federal University of Rio Grande do Sul, used advanced techniques to pinpoint the location of this monstrous black hole. This discovery pushes the boundaries of what we know about black holes and galaxy evolution.
What is the Cosmic Horseshoe?
The Cosmic Horseshoe is a rare alignment in space. First identified in 2007, this “horseshoe” is a near-perfect example of a gravitational lens. This is where a massive foreground galaxy warps the light of a background galaxy, creating an arc-like appearance.
In this scenario, the background galaxy appears as a luminous arc encircling the lensing galaxy, forming what’s called an Einstein Ring. The lensing galaxy, named LRG 3-757, is a giant elliptical galaxy that shines brightly in infrared light.
Measuring the Ultramassive Black Hole
How do scientists measure black holes that are so far away? Researchers used the motion of nearby stars and gas to estimate the black hole’s mass. However, at over five billion light-years away, direct observations are tough.
Melo-Carneiro and his team innovatively combined data from the Multi Unit Spectroscopic Explorer (MUSE) instrument on the Very Large Telescope with high-resolution images from the Hubble Space Telescope. This created a combined model of the galaxy’s mass.
The team’s innovation was incorporating the gravitational lensing distortion of background light and the movement of stars within the lensing galaxy. The result was a precise mass estimate of the central black hole, weighing in at an astonishing 36 billion solar masses.
Beyond What Was Thought Possible
Astronomers have long known that supermassive black holes reside at the centers of most large galaxies. Their masses tend to follow a predictable pattern, known as the MBH–σe relation, which is based on the speed at which stars move in the galaxy’s center.
But the black hole in LRG 3-757 doesn’t follow this trend.
This black hole’s mass is about 1.5 standard deviations above what the MBH–σe relation would predict, based on the velocity dispersion of 366 km/s. This hints at an unusual past or present in the galaxy.
Why This Ultramassive Black Hole Is So Big
Several theories attempt to explain this deviation. One possibility is that LRG 3-757 has a dramatic history of mergers.
Another explanation is AGN feedback, where a feeding black hole pumps energy into its surroundings, disrupting star formation and changing the galaxy’s internal structure. There’s also a chance that this black hole is a remnant of an ancient quasar, which rapidly grew by consuming vast amounts of matter.
Deviant Ultramassive Black Holes
This study adds to the growing list of ultramassive black holes that defy the expected galaxy-black hole scaling laws. The significance of this finding lies in its distance.
We see the Cosmic Horseshoe as it was over four billion years ago. It is also one of the most massive black holes ever directly measured at any redshift. Future findings may challenge our understanding of how galaxies evolve.
With upcoming tools like the Extremely Large Telescope (ELT), scientists will be able to measure stellar dynamics with greater precision in galaxies that are billions of light-years away.
“This new era of discovery promises to deepen our understanding of galaxy evolution and the interplay between baryonic and dark matter components,” the authors concluded in their paper, published in the online journal Arxiv.
