Space and Physics
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We are seeing farther back into the universe than ever before. JWST has been able to peer at galaxies located at incredible distances. The most distant yet was announced last year, and now it has been confirmed. MoM-z14 is currently the most distant galaxy known.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.MoM stands for “Mirage or Miracle” from the eponymous survey. The MoM survey aims to confirm whether the objects that appear to be very distant are truly there or not. MoM-z14’s light comes from 280 million years after the Big Bang, truly at a time that models suggested galaxies were only just forming.
The discovery of MoM-z14 and other examples of surprisingly bright galaxies in the early universe is bringing those models into question. These galaxies are 100 times brighter than theoretical studies predicted, suggesting that these galaxies were extremely active and rushing to get older.
“There is a growing chasm between theory and observation related to the early Universe, which presents compelling questions to be explored going forward,” team member Jacob Shen, a postdoctoral researcher at MIT, said in a statement.
An interesting finding from MoM-z14 is the presence of nitrogen, more than should be possible to produce by that time. It suggests that conditions in the early universe might have been different from what we thought, and maybe to understand those distant stars, we should look at peculiar ones in our own galaxy.
MoM-z14 also shows signs of clearing out the thick fog of neutral hydrogen that is expected to exist across the universe at the time. The powerful light of those very puzzling stars has been crucial to that. The clearing happens when the light rips electrons from the hydrogen atoms, ionizing them. Given that the hydrogen in the universe formed without electrons, and this is the second time that it happened, this period is known as the epoch of reionization.
Studying galaxies at that time can provide more clues about this mysterious period in the history of the universe. But it is difficult to find them, hence the MoM Survey. Due to the expansion of the universe, the light of these galaxies is stretched into longer wavelengths, so these objects appear redder.
But objects might appear redder for other reasons, so these candidates need to be followed up with a spectrograph, which can confirm just how much the light has been redshifted, thus providing a value of how far away it is.
“We can estimate the distance of galaxies from images, but it’s really important to follow up and confirm with more detailed spectroscopy so that we know exactly what we are seeing, and when,” added Pascal Oesch of the University of Geneva in Switzerland, co-principal investigator of the survey.
The study is due to be published in the Open Journal of Astrophysics, and a preprint version is currently posted to arXiv.
