His exact name is Mom-Z14but the astronomers who discovered it nicknamed him Cosmic Miracle“Cosmic miracle”: it is a galaxy recently observed by the space telescope James Webb and that proved to be the most distant ever discovered so far. Do you think his light has only started 280 million years After the Big Bang: this means that to reach us he traveled over 13.5 billion years, 98% of the age of the universe! The new record It exceeds that obtained by James Webb (who also has the merit of having discovered the most distant star ever observed) just a year ago, when the space telescope discovered two galaxies whose light dates back to 290 million years after the Big Bang.
But it is not so much the primacy that makes this discovery important, but the fact that his remarkable brightness In such a primordial cosmic era challenges our knowledge about the early stages of the life of the cosmos, potentially helping us to unravel One of the great mysteries of modern astronomy: understand how and when the first galaxies formed.
What we know about Mom-Z14, the most distant galaxy
Mom-Z14 is a galaxy in formation and therefore of small size: let’s talk about just 240 light years in diameter, comparable to those that in today’s universe we can expect for a globular clusterthat is, a spherical distribution composed of a few hundred thousand stars. For comparison, the album of our Milky Way has a diameter of about 100,000 light years.
Despite his compactness, Mom is very bright especially in the electromagnetic band of theultravioletenergy radiation typical of very massive stars and generally associated with a high star training rate. The strong ultraviolet component in the light emission of this galaxy also indicates that a large part of its brightness derives from stars and not from the activity of a central supermassive black hole (what the astronomers call “active galactic core“) As often happens for very young galaxies. It also looks like a relatively poor galaxy of dust.
The analysis of the light emitted by this remote galaxy has highlighted a significant amount of nitrogen And carbontwo chemical elements that were not present in the primordial universe and need previous star generations to be spread in the environment. In fact, the atomic nuclei of the most “heavy” atoms of lithium are produced through thermonuclear merger in the heart of the stars and expelled to the death of these stars. In short, having such a young galaxy but already with significant abundance of “heavy” elements implies that has already had at least one generation of stars Fatte massive to produce and release nitrogen and carbon.
Because the discovery is important
The information collected on Mom-Z14 tells us about a galaxy very “early”enough to challenge the theoretical models of galactic formation. It is a very bright galaxy, low in dust and rich in heavy elements to find yourself in a cosmic era so far in time and close to the Big Bang. This observation – together with others who have come in recent years also thanks to the excellent skills of the James Webb space telescope – suggest that The primordial universe had been more active and frenetic how much astronomers expected on the basis of the theoretical models available to them.
From this point of view, increasing our “catalog” of distant galaxies can help us understand what the astrophysical and cosmological mechanisms that led to the formation and (rapid) evolution of the first galaxies have been.
