Why Black Holes Never Run Out of Fuel
New research reveals how black holes sustain themselves.
1The Growth Paradox of Black Holes
Nearly every large galaxy in the universe harbors a supermassive black hole at its center, with masses ranging from millions to billions of times that of the sun. These black holes grow by consuming surrounding matter while also ejecting powerful energy jets. These jets heat the surrounding gas, delaying the formation of new stars and affecting the galaxy's growth. However, this process implies that black holes should eventually exhaust their fuel sources. So why don't they run out of fuel?
2The Role of Filaments
Researchers proposed a hypothesis to explain how black holes sustain their fuel supply: Gas blown away by heat eventually cools in interstellar space and condenses into thin, thread-like structures called filaments. These filaments then fall back toward the black hole. This hypothesis suggests a self-sustaining cycle for black holes. A new study has brought scientists closer to confirming this idea.
3Observations of NGC 4696
An international team led by Professor Julie Hlavacek-Larrondo from the University of Montreal observed the central galaxy NGC 4696 in the Centaurus Cluster. Using the James Webb Space Telescope's Near-Infrared Spectrograph (NIRSpec), the team conducted observations for about eight hours, achieving a resolution fine enough to distinguish structures as small as 30 light-years across. These observations directly visualized how filaments supply fuel to the black hole.
4The Rotating Gas Disk
The observations revealed that the S-shaped spiral structure at the center of NGC 4696 is actually a rotating disk of gas orbiting the black hole. The disk is approximately 800 light-years in diameter, with gas pulled by the black hole's immense gravity rotating at several hundred kilometers per second. A velocity difference of about 600 kilometers per second was measured between opposite edges of the disk, providing crucial evidence of how gas is drawn into the black hole.
5Fuel Supply Mechanism
The observations also showed that filaments—formed from condensed gas—flow directly into the edge of the disk. Gas travels along these filaments, accumulates in the disk, and is ultimately supplied to the black hole as fuel. This marks the first time the entire fuel supply pathway has been directly imaged. Julie Hlavacek-Larrondo stated, 'What JWST is revealing is that black holes may be the ultimate cosmic recyclers.'
6The Influence of Magnetic Fields
In addition to observations, the research team conducted computer simulations. The simulations showed that as filamentary gas falls toward the black hole, stretched magnetic fields act like ropes, removing the gas's angular momentum and allowing it to fall into the disk. The disk's axis wobbles due to gas flowing in from multiple directions, causing the energy jets' direction to shift. This ensures the jets heat the galaxy cluster's central region more uniformly.
7Conditions in Other Galaxies
The researchers noted that in the central galaxies of other clusters, where black holes produce even more powerful energy jets, the gas may remain in a chaotic state without forming a disk. This means the strength of a black hole's activity can fundamentally alter the behavior of surrounding gas. These findings are critical for understanding black hole evolution and galaxy growth.
8Future Research
This publication is the first in a series of three papers based on JWST observations. While the current study focused on relatively warm gas at around 10,000 Kelvin, additional papers analyzing gas behavior at other temperatures are in preparation. The discovery has also led to the approval of new observing programs using JWST and coordinated observations with telescopes worldwide. Researchers are now accelerating their search for evidence to determine if similar cosmic recycling systems operate in other galaxies.
Original article: Science Latest — Kara Deliklerin Neden Hiç Yakıtı Bitmiyor?