Black Hole Jets Pack Surprising Punch in Early Universe

Black holes in the distant universe are blasting out jets with far more energy than scientists expected, according to new research using NASA’s Chandra X-ray Observatory.

These cosmic cannons are firing at nearly the speed of light during what astronomers call “cosmic noon” – a critical period about three billion years after the Big Bang when galaxies and black holes were growing faster than ever before.

The discovery centers on two supermassive black holes located over 11 billion light-years away. Scientists found that one jet carries roughly half as much energy as the intense light from hot gas swirling around its black hole – a ratio that suggests these ancient cosmic engines packed more punch than previously thought.

Racing Against Physics

“We’re finding that some black holes may carry a bigger punch at this stage in the universe than we thought,” said Jaya Maithil of the Center for Astrophysics | Harvard & Smithsonian, who led the study.

The jets are moving at breakneck speeds between 92% and 99% of the speed of light. “These jets are going so fast that they are pushing up against the absolute speed limit of physics – the speed of light,” explained co-author Aneta Siemiginowska, also of CfA.

What makes these observations particularly remarkable is how the jets become visible to Earth-based telescopes. As electrons in the jets race away from their black holes, they collide with photons from the cosmic microwave background – the leftover glow from the Big Bang itself. These collisions boost the energy of the photons up into the X-ray band, allowing Chandra to detect them across billions of light-years.

Ancient Light Reveals Modern Mysteries

The cosmic microwave background was much denser 11 billion years ago than it is today, making this detection method particularly effective for studying early universe phenomena. “The X-rays are cosmic microwave photons amplified one million times by electrons accelerated by the supermassive black hole,” said co-author Dan Schwartz, also of CfA.

Using both Chandra and the Karl G. Jansky Very Large Array, researchers identified jets stretching over 300,000 light-years from their black holes. However, they found an intriguing discrepancy: while X-ray emissions clearly traced the jet paths, continuous radio signals matching the X-ray jet lengths weren’t detected.

This difference makes perfect sense, scientists explain. Electrons producing radio waves don’t last as long as those creating X-rays through cosmic microwave background interactions. The enhanced X-ray emission is expected, but radio emission isn’t necessarily continuous.

Beyond Press Release Findings

The research revealed that these distant jets point almost directly toward Earth – within about 10 degrees of our line of sight. This precise alignment helps explain their remarkable brightness and provides crucial data for understanding jet mechanics. The team used sophisticated Bayesian analysis to break the usual mathematical deadlock between bulk motion factors and viewing angles that has long plagued jet studies.

Additionally, the magnetic field measurements show typical values for jets producing X-rays via cosmic microwave background interactions, with field strengths ranging from 6 to 105 microGauss depending on viewing geometry.

Cosmic Archaeology

The research offers a unique window into cosmic noon, when most galaxies and supermassive black holes experienced their fastest growth periods. Scientists can use these jet observations to probe fundamental questions about how black holes helped shape their galactic neighborhoods during this crucial era.

The jets represent substantial energy output – one carries a kinetic power of approximately 5×10^46 ergs per second, roughly 50% of its black hole’s total light output. This substantial energy transfer suggests these ancient jets played significant roles in galaxy evolution and feedback processes.

For one quasar, researchers found jet kinetic power reaching about half the object’s total energy output, while the other showed more modest ratios around 2%. These measurements help scientists understand the relationship between black hole feeding and energy ejection during the universe’s most active period.

The findings were presented at the American Astronomical Society meeting and published in The Astrophysical Journal, offering new insights into how the universe’s most powerful engines operated during its formative years.

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