Researchers discover monster galaxies nearly the size of the Milky Way lurking in The Early Universe

In the early Cosmos, long before they should actually have had time to grow, astrophysicists have found what they’re terming ‘red monsters’: three large galaxies, nearly as big as the Milky Way. It’s a startling discovery for various reasons – not least of which is the contradiction it poses to our conventional understanding of how galaxies came into being, back when time and space were mewling neonates in the void. “The question of ‘impossibly’ massive galaxies shortly after the Big Bang has vexed astronomers ever since the first images of the James Webb Space Telescope,” says astrophysicist Ivo Labbé of Swinburne University of Technology. “This is akin to finding a toddler weighing 100 kilograms. JWST has now proven monsters do roam the early Universe.”

Based on mindful observation and analysis, we have a very good idea about how many cosmic processes unfold. But one significant time period eludes us: the early Universe, also known as the Cosmic Dawn, the first billion years succeeding the Big Bang. We have some ideas about how speedily the Cosmos assembled itself from the primordial plasma that permeated the early universe, but observational evidence has been a little tougher to obtain. With the advent of James Webb Space Telescope, we’ve been able to gather that evidence. As the far reaches of space ebb, the light from substances within is stretched to the infrared wavelengths with which the powerful space telescope views the Cosmos, giving us the strongest probe yet for the Cosmic Dawn.

According to our conventional models, galaxies take some time to assemble and grow. We’re not utterly sure of the particulars, but the most popular model involves blobs of dark matter, into which baryonic (or normal) matter is gravitationally gathered. As more and more baryonic matter amasses, it begins to coalesce into stars, swirling around a giant black hole in the galactic center.

Although galaxies appear quite quickly after the Big Bang, the rate at which they grow was believed to be too slow for colossal galaxies to emerge during the Cosmic Dawn. So, when JWST turned its golden eye towards the early Cosmos, and started seeing signs of larger-than-expected galaxies there, astronomers and cosmologists were perplexed.

One explanation offered earlier is that those over-large galaxies are not actually as big as they look; the light released from material around their central black holes is just too bright, making the galaxies seem bigger than they are. And a recent discovery bared the fact that black holes can, for brief periods, lighten up their galaxies to very high brightness.

This may be the case for many of the galaxies. But the new research, led by astrophysicist Mengyuan Xiao of the University of Geneva in Switzerland, shows that, in at least few cases, when it seems like a colossal galaxy and quacks like a colossal galaxy, it is indeed a massive galaxy.

The observations were carried out for JWST’s FRESCO program, an international collaboration to get accurate distance and mass measurements for galaxies present in the early Universe. Most of the galaxies the team studied fit the prevailing models for galaxy evolution, but three really stood out as abnormal.