Largest radio jet ever seen provides a glimpse of the young universe

For decades, astronomers have known that supermassive black holes lie at the centers of most galaxies. These gravitational giants devour infalling gas and dust, releasing extraordinary amounts of energy that can outshine entire star systems. 

When this infall generates particularly energetic flows, the central black hole can launch powerful jets – narrow beams of high-speed particles that can extend for hundreds of thousands of light-years. 

Observations of cosmic jets

Radio jets are commonly observed in our local universe, but they have been notably elusive in the distant, early universe, where galaxies were forming and evolving under very different conditions.

Now, a team of astronomers has detected a radio jet at least 200,000 light-years in extent – twice the diameter of the Milky Way – in a young quasar known as J1601+3102.

This discovery stands as the largest radio jet yet found at such an early epoch, when the cosmos was less than 10% of its present age. 

The jet was initially spotted by the Low Frequency Array (LOFAR), an international network of radio telescopes distributed across Europe.

The hunt for early cosmic jets

Because radio jets are relatively common in the nearby universe, many astronomers have speculated that they must also have existed in the early cosmos. 

However, strong background noise from the cosmic microwave background (CMB) – a relic of the Big Bang – often drowns out the faint signals of distant jets. That is why, until now, astronomers had failed to detect large-scale jets from this primordial era.

The new detection came as a surprise. While examining radio data from LOFAR, the team noticed a faint, elongated structure near the quasar J1601+3102. Upon closer inspection, they realized they were looking at an enormous, two-lobed jet shooting out from the quasar’s center. 

Because J1601+3102 is located so far away, its light has taken nearly 12 billion years to reach us. The jet effectively provides a glimpse into the young universe, at a time when it was just 1.2 billion years old.

Anniek Gloudemans is a postdoctoral research fellow at NOIRLab and the lead author of the study. 

“It’s only because this object is so extreme that we can observe it from Earth, even though it’s really far away,” noted Gloudemans. “This object shows what we can discover by combining the power of multiple telescopes that operate at different wavelengths.”

Surprising origins of the radio jet

To better understand the jet and its origins, the astronomers conducted follow-up observations across multiple wavelengths. They used the Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, part of the International Gemini Observatory, as well as the Hobby Eberly Telescope for optical data.

The team analyzed the MgII (magnesium) broad emission line – originally emitted in the ultraviolet but stretched into the near-infrared by the universe’s expansion.

The researchers determined that the black hole powering J1601+3102 is relatively modest, at 450 million solar masses. Many quasars contain black holes billions of times the Sun’s mass, so this quasar’s “lighter” black hole was unexpected given the size of its radio jet.

“Interestingly, the quasar powering this massive radio jet does not have an extreme black hole mass compared to other quasars,” said Gloudemans. “This seems to indicate that you don’t necessarily need an exceptionally massive black hole or accretion rate to generate such powerful jets in the early universe.”

Moreover, the radio lobes appear asymmetrical in both brightness and extent, hinting at environmental factors that may shape the outflow. The difference could arise from interactions with surrounding gas, or from changes in the density of matter in different directions around the quasar.

Hidden radio jets

In addition to the intense CMB background, other processes in the young universe may have stifled or masked early jets, explaining why astronomers have seldom spotted them until now. 

Some scientists propose that powerful feedback mechanisms – such as supernova winds or intense star formation – could disrupt or hide these jets. J1601+3102, by contrast, appears so unusual that even these challenges could not fully obscure its cosmic beacon.

Frits Sweijen is a postdoctoral research associate at Durham University and co-author of the paper. 

“When we started looking at this object we were expecting the southern jet to just be an unrelated nearby source, and for most of it to be small,” said Sweijen.

“That made it quite surprising when the LOFAR image revealed large, detailed radio structures. The nature of this distant source makes it difficult to detect at higher radio frequencies, demonstrating the power of LOFAR on its own and its synergies with other instruments.”

Rare snapshot of early quasar activity 

This discovery illuminates how supermassive black holes may have influenced galaxy formation during the universe’s early epochs. Jets can inject energy into their surroundings, regulating star formation by heating or expelling gas. 

Understanding how these processes played out in the first billion years can shed light on why galaxies look the way they do today.

Despite this milestone, many questions remain. Researchers are unsure how frequently such jets formed in the early universe, or what specific conditions enable powerful outflows around less massive black holes. 

Future observations with cutting-edge facilities such as the James Webb Space Telescope (JWST), the Atacama Large Millimeter/submillimeter Array (ALMA), and the upcoming Square Kilometer Array (SKA) will provide deeper insights into these processes.

By revealing a massive radio jet at a time when the cosmos was still in its infancy, J1601+3102 offers a rare snapshot of early quasar activity. 

As astronomers continue to survey the distant universe, they may find more examples of these spectacular jets, drawing an increasingly detailed picture of how black holes and their galaxies co-evolved – and how the energy from these colossal engines shaped the cosmos.

The study is published in The Astrophysical Journal Letters.

Image Credit: NOIRLab/NSF/AURA/M. Garlick

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–