Most distant space laser discovered

Astronomers have identified the most distant and brightest space laser yet, a powerful radio signal originating from a collision between two galaxies when the universe was about half its current age.

Signal comes from a galactic collision

The signal, detected from a system known as HATLAS J142935.3–002836, is believed to be a gigamaser—a phenomenon where hydroxyl molecules amplify radio waves, similar to how lasers amplify light. This emission was discovered using data from the MeerKAT radio telescope in South Africa.

Signal detected in a short observation

The signal was identified in just a few hours of observation. It is located at a redshift of 1.027, meaning the light has traveled more than 8 billion years to reach Earth. The waves were emitted long before Earth existed.

Hydroxyl molecules amplify the signal

The signal has a wavelength of about 18 centimeters, which is the signature of hydroxyl molecules. These molecules can amplify radiation at specific frequencies, creating a maser effect. When this occurs in other galaxies, it is called a hydroxyl megamaser.

Gigamaser classification proposed

The intensity of the signal near the frequencies of 1667 and 1665 MHz led researchers to propose the term gigamaser. Thato Manamela, a researcher at the University of Pretoria, described the phenomenon as "the radio equivalent of a laser, located halfway through the universe."

Gravitational lensing enhances the signal

A foreground galaxy acts as a gravitational lens, bending spacetime and focusing the signal toward Earth. This effect does not create new light but redirects more of it, making the signal visible from Earth.

Previous observations suggest lensing effect

Images from the Hubble Space Telescope and the Atacama Large Millimeter/submillimeter Array had previously shown a partial Einstein ring around the system, indicating the presence of gravitational lensing.

Galactic merger creates ideal conditions

The galactic merger that produced the signal is not a coincidence. Such mergers create dense, chaotic gas environments, which are favorable for hydroxyl amplification. Previous studies suggest the system has a high rate of star formation.

Multiple layers of gas present

The dataset also contains an absorption line from neutral hydrogen, indicating that the system has multiple layers of gas, not just molecular gas.

Research accepted for publication

The research, conducted by scientists at the South African Radio Astronomy Observatory, has been accepted for publication in Monthly Notices of the Royal Astronomical Society Letters and is available as a preprint on arXiv.

Future surveys may find more gigamasers

Manamela emphasized that the speed of this detection suggests that future surveys could uncover many more gigamasers. The team aims to find hundreds, if not thousands, of such systems.