ASKAP discovers a spectacular outflow in a nearby galaxy

 

Astronomers using the Australian Square Kilometre Array Pathfinder (ASKAP) — a cutting‑edge radio telescope system in Western Australia — have revealed a huge bipolar outflow of cosmic material emanating from a nearby galaxy called ESO 130‑G012. This discovery was made as part of ASKAP’s Evolutionary Map of the Universe (EMU) survey, which maps the radio sky in unprecedented depth. 

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The key findings are:

Bipolar outflow: Material is streaming away from the galaxy’s disk in two opposite directions, forming a gigantic hourglass‑shaped structure that extends far beyond the galaxy. 

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The outflow stretches at least 30 kiloparsecs (≈100,000 light‑years) above and below the disk — reaching into the galaxy’s halo on both sides. 

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Morphologically, this structure resembles a closed hourglass with a “waist” about 33,000 light‑years wide, centered on ESO 130‑G012’s star‐forming disk. 

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The radio emission that makes this outflow visible comprises a core, inner knots, a thin disk, a thick boxy disk, and X‑shaped wings that define the broad base of the hourglass. 

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 2. About the Host Galaxy — ESO 130‑G012

Some basic facts about the galaxy where this outflow was found:

It lies about 55 million light‑years away — relatively close in cosmic terms. 

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ESO 130‑G012 is an edge‑on spiral galaxy, meaning we see it from the side rather than face‑on. This orientation makes outflows above and below the disk easier to detect. 

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The galaxy has an estimated stellar mass of ~11 billion solar masses. 

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Its star formation rate is modest (≈0.2 solar masses per year), suggesting it’s not a classic starburst galaxy. 

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There’s also a supermassive black hole at the center, about 50 million times the mass of the Sun. 

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 3. How Was the Outflow Seen?

ASKAP detected the outflow using deep radio continuum imaging at 944 MHz, which allows astronomers to see faint radio emission from cosmic particles moving in magnetic fields — something optical telescopes often miss.

This kind of radio imaging is perfectly suited to uncover large‑scale structures like galactic outflows and halos because:

It doesn’t suffer from dust obscuration the way optical or infrared observations do.

It’s sensitive both to relativistic electrons and magnetic fields — key components of galactic winds and outflows.

In the case of ESO 130‑G012, only deep radio maps revealed the full hourglass shape and extended lobes rising above the galaxy’s disk. 

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 4. What’s Creating the Outflow?

Researchers propose several possible mechanisms:

 Star Formation and Stellar Feedback

The galaxy’s stellar disk forms stars that generate strong winds and supernova explosions.

These processes can drive material out of the plane of the galaxy and into the halo, particularly in systems with a lower gravitational pull like this one. 

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 Cosmic Rays and Magnetic Fields

Cosmic rays (high‑energy particles from stellar processes) and magnetic fields can also help push matter outward and shape the outflow structure.

 Past Black Hole Activity

Even though ESO 130‑G012’s black hole doesn’t appear extremely active now, it might have been more active in the past, contributing to the outflow. 

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At present, the exact mix of mechanisms is still uncertain — follow‑up observations across multiple wavelengths (X‑rays, ultraviolet, optical, and spectral line mapping) will help clarify the dominant drivers of this outflow.

 5. Why This Matters

This discovery is significant for several reasons:

 A Rare Large‑Scale Outflow in a Normal Galaxy

Outflows this dramatic are more often seen in starburst galaxies or those hosting powerful active galactic nuclei (AGN). Finding one in a relatively calm galaxy challenges our understanding of how modest stellar feedback can influence a galaxy’s environment. 

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 Insights into Galaxy Evolution

Galactic outflows are critical for regulating the cycle of matter in galaxies. They can:

Carry gas out of a galaxy, suppressing future star formation.

Enrich the surrounding intergalactic medium with heavy elements.

Influence how cosmic rays and magnetic fields shape galaxy halos.

This discovery provides a new laboratory to study these processes. 

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 ASKAP’s Capabilities

The result demonstrates how wide‑field, high‑sensitivity radio surveys like EMU can uncover unexpected phenomena in nearby galaxies — even ones that look ordinary in optical light.

 What’s Next?

The authors of the study emphasize the need for:

Follow‑up observations across different wavelengths to trace gas temperatures and compositions.

Spectral line studies to measure the motions of gas in and around the outflow.

Modeling the disk‑halo interface, to understand how such enormous flows are launched and sustained.

ESO 130‑G012 now stands out as a compelling target for future research into how galaxies evolve over time and how energetic outflows shape their surroundings. 

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