The Universe is transparent. Light from galaxies and stars shines against a dark background.
But this wasn’t always the case – in its early years, the Universe was filled with a fog of hydrogen atoms that obscured light from the earliest stars and galaxies.
It is believed that the intense ultraviolet light of the first galaxies and stars burned through the fog of hydrogen, transforming our Universe.
Astronomers now use the latest generation of telescopes to study these early cosmic objects. James Webb Space TelescopeSuperior technology of’s to study the stars, galaxies and other objects that formed after the Big Bang.
I am an Astronomer studies galaxies at the furthest distanceThe world’s most advanced ground-based and space-based telescopes will allow you to explore the Universe.
My team has been able to make new discoveries using the Webb Telescope and a phenomenon known as gravitational lenses. Confirmation of existenceThe faintest galaxy known to date in the early Universe.
JD1 is the galaxy as it appeared when the Universe had only 480,000,000 years, or 4% of its current age.
Brief history of the early Universe
The first billion of the Universe’s existence were a Its evolution has a crucial phase. In the early moments of the Big Bang, light and matter were inextricably bound together by a dense, hot “soup”. fundamental particles.
But a fraction after the Big Bang the Universe began to form. Expansion is extremely rapid.
This expansion eventually allowed the Universe to cool enough for light and matter to separate out of their “soup” and – some 380,000 years later – form hydrogen atoms.
The Universe was in darkness, as hydrogen atoms were seen as an intergalactic cloud. There was no light coming from the stars or galaxies. This period is known by the The darkest ages of history.
The Universe was bathed in UV light when the first galaxies and stars appeared, several hundred million year after the Big Bang. burned – or ionized – the hydrogen fog. This is a process that can be used.This has led to the beautiful, transparent and complex Universe we know today.
Astronomers like me call the first billion years of the Universe – when this hydrogen fog was burning away – the Reionization epoch.
For a full understanding of this time period we need to know when the first galaxies and stars formed, their main characteristics, and whether or not they could produce enough UV to burn all the hydrogen.
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The search for faint galaxy in the early Universe
It is important to confirm the distances between galaxies and the astronomers who think they are responsible for the epoch.
Astronomers use telescopes to observe the stars because light has a limited speed and takes a while to reach them. View objects in their past.
It takes light from our Milky Way galaxy about 27,000 to reach Earth. So, we see what it looked like 27,000 ago. This means that we need to search for objects far away if we wish to be able to see the Universe’s very first moments (the Universe has a 13.8 billion-year history).
Due to the distance of galaxies that reside in this time period, they appear extremely distant. Small and faintThey emit the majority of their light through infrared. To find them, astronomers must use powerful infrared scopes such as Webb.
Webb’s telescope was able to reveal fainter, smaller galaxies that were previously invisible.
The brighter ones are not likely to drive the process of reionization. Instead, the more intelligent people will be.
Astronomers must study these faint galaxies in more detail. You can’t understand human evolution by studying a small group of tall people. Webb’s ability to detect faint galaxies opens up a whole new way of studying the early Universe.
A typical early galaxie
JD1 is a “typical” faint galaxie. It was Discovered in 2014 by the Hubble Space TelescopeAs a suspect galaxy. But Hubble didn’t have the capabilities or sensitivity to confirm its distance – it could make only an educated guess.
Nearby, there are small and faint objects It is possible to mistake distant galaxies for those that are closer.Before we can claim their properties, astronomers must be certain of their distance. Distant galaxies remain “candidates”, until they are confirmed.
JD1 is one of the most distant galaxies confirmed by Webb. This confirms it as The faintest galaxies yet observed in the early Universe.
Webb’s near-infrared telescope was used to confirm JD1 by an international team. NIRSpecTo obtain the infrared spectrum, of the galaxy.
The spectrum allows us to determine the distance of the star from Earth, its age and how many young stars it has produced.
Magnifying nature with gravitational lensing
Webb himself would not be able to see JD1 if it weren’t for nature. JD1 is hidden behind a large group of nearby galaxies known as Abell 2744whose combined gravity strength bends the light from JD1.
This effect is known as gravitational lenses and makes JD1 seem larger and more bright than it would normally be.
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Astronomers would have missed JD1 even with Webb without gravitational-lensing.
Combining JD1’s gravitational magnifying lens with new images taken by another of Webb’s Near-Infrared Instruments. NIRCamOur team was able to study the structure of the galaxy in unprecedented detail.
It is possible to study the inner regions, but also determine if these galaxies were compact, isolated, small sources, or whether they were merging with other galaxies.
By studying these galaxies we can trace back the building blocks of the Universe that gave birth to our home in the cosmos.
Guido Roberts-BorsaniPostdoctoral Researchers in Astrophysics University of California Los Angeles
This article was originally published by The ConversationCreative Commons licensed. The Licensed Terms are available here. Original Article.
