What is a megamaser? Premium

Discover the fascinating world of hydroxyl megamasers, powerful cosmic lasers revealing secrets of distant galaxies and the universe's evolution.

A: Last, astronomers reported finding the most distant hydroxyl maser yet using the MeerKAT telescope.

A hydroxyl megamaser is a giant and naturally occurring laser found in deep space. Just as a regular laser focuses visible light into a concentrated beam, a maser focuses microwave or radio waves.

The ‘hydroxyl’ part refers to a simple molecule made of one oxygen atom and one hydrogen atom (OH–). These molecules float in large clouds of gas within distant galaxies. When two galaxies collide, the impact triggers intense star formation and feeds giant black holes, and also releases massive amounts of infrared energy.

When this energy strikes the hydroxyl molecules, it pumps them into a high-energy state. As the molecules settle back down, they release a powerful, amplified beam of radio waves. Astronomers call these signals megamasers because they shine millions of times brighter than the smaller masers found in our own Milky Way galaxy.

Astronomers treat these beams as cosmic beacons. Because the radio waves can travel through thick dust, scientists can study them to reveal where they came from and how they could’ve been produced, even if the source is obscured. In turn, they can measure how fast galaxies are moving and better understand the evolution of the universe.

This newfound megamaser is from a galaxy billions of lightyears away. A natural cosmic lens magnified its emission, making it the brightest ever seen and earning it the moniker ‘gigamaser’.