Consuming matter at over 40 times its theoretical limit

Astronomers using data from NASA’s JWST and Chandra X-ray Observatory have discovered a supermassive black hole in a galaxy just 1.5 billion years after the Big Bang. The black hole consumes matter at more than 40 times the theoretical limit.

Although short-lived, this rapid growth could provide important clues about how supermassive black holes grew so quickly in the early Universe, helping to explain their surprising presence at the centers of many galaxies today.

LID-568, a galaxy with intense X-ray emissions, was discovered by a cross-institutional team led by Hyewon Suh of the International Gemini Observatory/NSF NOIRLab. The team used the James Webb Space Telescope (JWST) to study galaxies from the Chandra X-ray Observatory’s COSMOS legacy survey.

These galaxies are bright in X-rays but invisible in the optical and near-infrared, making JWST’s infrared sensitivity essential for detecting faint emissions.

LID-568 stood out for its strong X-ray signal, but its exact position was unclear from the X-ray data alone, creating challenges in aligning it with JWST’s field of view.

Suh’s team addressed this using JWST’s NIRSpec integral field spectrograph. This spectrograph captures a spectrum for each pixel in its field of view, offering a more precise way to locate and analyze the galaxy.

Emanuele Farina, International Gemini Observatory/NSF NOIRLab astronomer, said, “Owing to its faint nature, the detection of LID-568 would be impossible without JWST. Using the integral field spectrograph was innovative and necessary for getting our observation.”

Using JWST’s NIRSpec, the team obtained a comprehensive view of LID-568 and its surrounding region. This revealed powerful gas outflows around the galaxy’s central black hole.

The size and speed of these outflows suggested that a significant portion of LID-568’s mass growth may have occurred during a single, rapid accretion event, offering new insights into the processes driving the growth of supermassive black holes in the early Universe.

In a groundbreaking discovery, Suh and her team found that LID-568 consumes matter at a rate 40 times higher than its Eddington limit. The Eddington limit defines a black hole’s maximum luminosity, balancing the inward gravitational pull and the outward pressure from the heated, infalling material.

When the team calculated LID-568’s luminosity to be so far beyond this theoretical limit, they realized they had uncovered something extraordinary. This discovery offers new insights into the extreme feeding behaviors of black holes in the early Universe.

International Gemini Observatory/NSF NOIRLab astronomer and co-author Julia Scharwächter said, “This black hole is having a feast. This extreme case shows that a fast-feeding mechanism above the Eddington limit is one of the possible explanations for why we see these hefty black holes so early in the Universe.”

These findings offer new insights into how supermassive black holes may form from smaller “seed” black holes, addressing a long-standing gap in our understanding. Current theories propose two possible origins for these seed black holes: they could either form from the death of the Universe’s first stars (light seeds) or the direct collapse of gas clouds (heavy seeds). Until now, no observational evidence has confirmed these theories, but the discovery of LID-568’s rapid growth and extreme feeding could provide crucial clues to the black hole formation process in the early Universe.

International Gemini Observatory/NSF NOIRLab astronomer Hyewon Suh said, “The discovery of a super-Eddington accreting black hole suggests that a significant portion of mass growth can occur during a single episode of rapid feeding, regardless of whether the black hole originated from a light or heavy seed.”

The discovery of LID-568 also demonstrates that a black hole can exceed its Eddington limit, providing the first opportunity for astronomers to study this phenomenon. The team speculates that the powerful gas outflows observed around the black hole could act as a “release valve,” dissipating the excess energy produced by the extreme accretion and preventing the system from becoming unstable.

To better understand these mechanisms, the team plans to follow up observations with JWST to explore how such rapid accretion and outflows impact the growth and stability of supermassive black holes.

Journal Reference:

1. Suh, H., Scharwächter, J., Farina, E.P. et al. A super-Eddington-accreting black hole ~1.5 Gyr after the Big Bang observed with JWST. Nat Astron (2024). DOI: 10.1038/s41550-024-02402-9