MeerKAT has picked up a distant signal that stands out through sheer power alone. The telescope captured it from a galaxy system labeled H1429-0028. Its light has been traveling toward Earth for more than eight billion years. The signal is produced by hydroxyl molecules inside a chaotic merger of galaxies on the far side of the universe. The strength of this emission places it at the top of the list of known hydroxyl sources at similar distances.
The source sits behind a foreground galaxy that acts like a natural magnifier. The lensing turns the background structure into an almost complete ring and lifts its brightness far beyond what it would be otherwise. The lensing galaxy lies closer to Earth. The background system lies farther away with two main infrared cores, large clouds of molecular gas and intense far infrared output. These conditions allow hydroxyl molecules to release intense radio energy that becomes visible across cosmic distances.
MeerKAT recorded this energy across only a few hours of observation. The signal rose sharply above the surrounding noise and reached a strength that leaves no doubt about its reality. The emission did not appear as one peak. It arrived as a group of five separate components, each carrying its own width and intensity. One feature was extremely tight. Another stretched across hundreds of kilometres per second. Together they formed a profile that carries the imprint of gas motion inside the distant galaxy.
Each peak sat at a specific frequency in the 822 to 823 megahertz range. The narrowest feature reached a width of only seven kilometres per second. The broadest covered more than three hundred kilometres per second. The tallest peak in the group rose well above the others in a narrow spike. All of these details appear directly in the observed numbers. No interpretation is required to appreciate their scale. The readings show fast moving gas, tightly concentrated hotspots and wider regions of motion combined into a single observable spectrum.
The total brightness reached values near log L 5.5 in solar units before any correction for magnification. Even when reduced by the expected magnification level, the signal remains one of the strongest known. The brightness does not follow a simple pattern. The spacing between the two highest peaks does not match the expected gap between the common hydroxyl lines in the observed frame. The difference between these features measured only 0.34 megahertz. The expected value would have been closer to 0.96 megahertz at this distance. This mismatch shows that the brightest features belong to different regions and not to a single pair of lines.
The lensing model built for this region shows how different areas of the background galaxy experience different levels of magnification. The eastern infrared nucleus and the diffuse region reach magnifications near ten for moderate source sizes. The western nucleus lies closer to the caustic where magnification climbs sharply. Very small regions placed there reach values over thirty. Compact maser spots often measure less than a hundred parsecs across. A region of that size positioned near the western nucleus would experience exactly the type of magnification boost that can produce an unusually bright narrow spike.
The system also contains neutral hydrogen gas. MeerKAT detected this as absorption against the background signal. This absorption appears in two components placed on either side of the system’s central velocity. Their depths fall under a millijansky. Their widths stay under fifty kilometres per second. The column densities reach over ten to the twenty first power when applying common assumptions for spin temperature and covering factor. These numbers stand on their own. They identify the presence of cold gas along the line of sight without any added explanation. The hydroxyl emission holds more negative velocities than these hydrogen components. The signal values show this directly. They do not occupy the same velocity range.
Carbon monoxide and atomic carbon lines recorded in earlier work show broader velocity widths than the hydrogen. Their central values align with the systemic velocity. The hydroxyl features do not. The offsets appear in the measured velocities for each component. The numbers show separate gas reservoirs with different motions inside the merging system. The far infrared output and dust temperature near forty Kelvin match values seen in other hydroxyl systems at similar distances. The radio to infrared ratio falls into the commonly observed range for star forming galaxies. Each of these values connects the source to known categories without requiring interpretation.
The magnification values as a function of source radius paint a clear picture using only numbers. A radius near 0.1 arcseconds yields magnifications close to ten for two of the nuclei. The western region climbs as the radius shrinks. Radii below one hundred parsecs push magnification beyond thirty. The narrow hydroxyl spike fits the type of region that would fall under this stronger boost. The broad emission fits the range where magnification stays closer to ten.
The relationships between far infrared output and hydroxyl luminosity follow the same numerical pattern documented for other systems. When magnification is included, the apparent luminosity aligns with predicted values. The system sits on the same curve traced by known hydroxyl emitters. The observed values require no commentary to establish this. They are part of the raw measurements.
The atomic hydrogen velocities sit at negative thirty six and positive eighteen kilometres per second. Their widths span the forty kilometre per second range. The hydroxyl peaks appear far more negative than those values. This difference appears directly in the velocity table. No interpretation is needed to recognize it. The carbon monoxide and carbon lines occupy a wider range with centres at the systemic value. The hydroxyl features do not share that alignment. The numbers define this separation clearly.
H1429-0028 stands out through scale alone. Its luminosity reaches the top of the known population. Its distance pushes the category into a regime that had very few confirmed examples. The signal displays multiple components, large velocity spreads, strong magnification effects and clear separation between different gas phases. Every one of these points comes from direct measurements. The facts stand on their own and deliver a clear image of a distant system producing powerful hydroxyl emission that MeerKAT captured with high precision.
Source:
MeerKAT discovery of a high redshift strongly lensed hydroxyl gigamaser (arXiv:2602.13396v1)
https://arxiv.org/abs/2602.13396v1
