When gas-rich galaxies collide, molecules called hydroxyl collide with each other, releasing very intense radio waves, which were then amplified by a rare effect called gravitational lensing, a phenomenon predicted by Albert Einstein
It is one mysterious signal “delivered” from the cosmos, but who already imagines being in the presence of something that smells alien, as contemplated by the famous film Contact by Robert Zemeckis, with Jodie Foster as the protagonist, must be reviewed another time. There is nothing associated with possible traces of extraterrestrial lifehowever the colossal beam of energy that is proceeding towards the Earth, from a distance estimated at at least 8 billion light yearsthat is, since the universe was about half its current age, is something extremely significant and important: it could in fact help us better understand the immensity that surrounds us.
The announcement of the discovery was signed by an international team of astronomers who captured it, taking advantage of the sensitivity and precision of the radiotelescopio MeerKAT placed in South Africa and equipped with 64 antennas, a “hydroxyl megamaser”. What is it about? From a giant natural laser placed in space. When gas-rich galaxies collide, molecules called hydroxyl they collide with each other releasing very intense radio waves. These waves behave like a laser, but instead of visible light, they produce radio signals that astronomers can detect with telescopes. Since these signals are extremely bright, they can be observed from enormous distances in the universe. In this case, the object is so powerful that scientists have speculated that it may be a “gigamaser“, even more powerful than a megamaser.
It was established that the signal comes from a binary system of colliding galaxies, called Hatlas J142935.3–002836, where the violent collision between gas clouds excited the hydroxyl molecules, triggering an amplified emission that acts as a beacon in the most remote areas of spacetime. Doctor’s comment Will Stickfrom the University of Pretoria, lead author of the study: «We have detected an extraordinary system because we are observing the radio equivalent of a laser right in the central part of the universe. As the radio waves traveled towards Earth they were amplified by a separate galaxy, positioned directly along the line of sight, acting like a lens or, to use a more immediate comparison, a a drop of water on a glass: its mass, in fact, curves local spacetime. So we have a radiolaser passing through a cosmic telescope before being detected by the powerful MeerKAT radio telescope, making for a wonderfully serendipitous discovery.”
The radio signal contained four distinct componentsmeaning it comes from multiple regions within the galactic system. At least two of these areas appear to be strongly amplified by the gravitational lensing effect, making the signal brighter than ten times what it would normally appear.
Normally signals from objects this far away are too weak to be detected by telescopes. But the very powerful one coming from Hatlas J142935.3–002836 was amplified by a rare effect called gravitational lensa phenomenon predicted by Albert Einstein. Gravitational lensing occurs when a massive object like a galaxy it comes between the Earth and a distant source. Its strong gravity curve spacetimechanging the path of light or radio waves that pass through it. This effect makes the distant signal appear brighter and magnified, allowing telescopes like the MeerKAT radio telescope to detect it even from billions of light-years away.
We were talking about the importance of this “meeting”. It is because by studying megamasers researchers can establish the rate of star formation within colliding galaxies, the mass of supermassive black holes in galactic nuclei and finally the rate of expansion of the universe. If further gigamasers are discovered, i.e. the “XL” version of megamasers, it will be possible to define a map of the evolutionary history of the cosmos.
