Astronomers led by a team from the University of Pretoria have made a groundbreaking discovery using South Africa’s MeerKAT radio telescope: the most distant and luminous hydroxyl megamaser ever observed. Announced by the South African Radio Astronomy Observatory (SARAO) on Tuesday, February 17, 2026, this "space laser" phenomenon is located in the system designated HATLAS J142935.3–002836 (often abbreviated as H1429-0028), more than 8 billion light-years from Earth.
The discovery, detailed in a peer-reviewed preprint submitted to arXiv on February 13, 2026 (arXiv:2602.13396), pushes the observational frontier for hydroxyl masers (OHMs) to unprecedented redshifts. At a redshift of z = 1.027, the light we detect today originated when the universe was less than half its current age—approximately 5.5–6 billion years old—offering a rare glimpse into early cosmic galaxy evolution during a period of intense star formation and mergers.
SARAO described the find as both the most distant and most luminous known hydroxyl megamaser. Its extraordinary brightness has earned it the upgraded classification of gigamaser, surpassing the typical megamaser threshold due to its immense intrinsic power amplified by natural cosmic effects.
Hydroxyl megamasers are natural cosmic amplifiers—often called "space lasers"—produced when hydroxyl (OH) molecules in the dense gas clouds of merging galaxies collide and undergo population inversion, emitting intensely bright radio signals at the characteristic 18-centimeter wavelength (rest frequencies around 1665 and 1667 MHz). These emissions are particularly prominent in gas-rich, dust-obscured environments like starburst galaxies or those hosting active galactic nuclei, making OHMs valuable tracers of extreme physical conditions, galaxy mergers, and high star-formation rates.
Despite its vast distance, the signal from HATLAS J142935.3–002836 reached Earth with remarkable strength thanks to a rare alignment: a foreground galaxy at z = 0.218 (an edge-on disk galaxy) acts as a gravitational lens, bending and magnifying the radio waves en route. This strong gravitational lensing—predicted by Einstein's general relativity—magnifies the source by factors of μ ≈ 8–10 across wavelengths, effectively turning the foreground galaxy into a "cosmic telescope."
Dr. Thato E. Manamela, a SARAO-funded postdoctoral researcher at the University of Pretoria and lead author of the study, explained: “This galaxy acts as a lens, the way a water droplet on a window pane would, because its mass curves the local space-time. So we have a radio laser passing through a cosmic telescope before being detected by the powerful MeerKAT radio telescope.”
The detection achieved a signal-to-noise ratio exceeding 150 in just 4.7 hours of MeerKAT observation time, demonstrating the telescope's exceptional sensitivity in the L-band. The spectrum shows blended main-line OH emission (1667 MHz and 1665 MHz) with a highly complex profile, featuring narrow components (<8 km/s) and broad wings (up to ~300 km/s), indicative of turbulent gas dynamics in the lensed merging system.
The background source itself is a major merger involving two components with a stellar mass ratio of roughly 1:3, plus a long tidal tail visible in multi-wavelength data from previous observations (including Herschel-ATLAS selection, HST, Keck, ALMA, and JVLA). It hosts a massive molecular gas reservoir (~4.6–5.9 × 10¹⁰ solar masses), fueling a star-formation rate of ~100–394 solar masses per year—typical of high-redshift dusty starbursts.
Manamela emphasized the broader implications: “This system is truly extraordinary... This is just the beginning. We don’t want to find just one system – we want to find hundreds to thousands.”
Previous OHM surveys were largely confined to low redshifts (z ≲ 0.25), limiting insights into their cosmic evolution. MeerKAT's wide-field, high-sensitivity capabilities—coupled with upcoming surveys like MIGHTEE and LADUMA—now enable systematic exploration of high-redshift OHMs. These sources can probe obscured star formation, feedback processes, and potentially even dual supermassive black holes in merging galaxies.
The discovery highlights South Africa's growing role in global radio astronomy. MeerKAT, a precursor to the Square Kilometre Array (SKA) mid-frequency array, continues to deliver transformative results, empowering local scientists like Dr. Manamela to lead international breakthroughs.
As teams analyze the full dataset—including a newly detected HI absorption line in the same observation—the find promises to deepen our understanding of galaxy assembly in the early universe. Future SKA observations could uncover populations of such gigamasers, revolutionizing studies of cosmic star formation history and extreme astrophysical environments.
