Looking far into space to analyze early universe timeline means peering back in time. The more distant the object, the earlier we see the Universe’s history. This is a way to see what the Universe was like shortly after the Big Bang.
Einstein’s theory of relativity and Time’s slower movement
Albert Einstein’s famous theory, the general theory of relativity, suggests that time appeared to move slower back in those early days of the Universe compared to now. Getting a peek at this slower Universe of the past was challenging. But scientists say they’ve done it by observing intense black hole entities known as quasars.
“When we gaze back to when the Universe was just over a billion years old, time seems to be moving at a pace five times slower,”says Professor Geraint Lewis from the University of Sydney, who guided the study.
“If you were in that young Universe, one second would feel like one second. But from our perspective, over 12 billion years later, time back then appears to be in slow motion.”
The scientific journal Nature Astronomy has reported on this study. The research group analyzed data from nearly 200 quasars to draw their findings about early universe timeline. These objects are black holes situated at the core of extremely lively galaxies.
“Einstein taught us that space and time are linked. Since the Big Bang, the birth of time, the Universe has been expanding,”says Professor Lewis.
As space expands, our observations of the early Universe should reveal time moving slower than now. In this paper, we’ve demonstrated that looking back to about a billion years after the Big Bang, In the past, astronomers could glimpse the slower Universe up to around half of its current age by studying supernovae, explosive endings of big stars.
Supernova analyzing early Universe timeline
These events can serve as “standard clocks” to show that time ran slower in the early Universe. But by observing quasars, scientists have witnessed slow motion dating back to just a tenth of the Universe’s age.
Professor Lewis explains,
“Supernovae are like single flashes of light, making them easy to study. Quasars, however, are more complex, like a continuous firework display.”
“We’ve managed to understand this firework display, proving that quasars can also be used as time markers for the early Universe.”
Collaborative discovery regarding early Univesre timeline
Professor Lewis and Dr. Brendon Brewer from the University of Auckland collaborated on the discovery concerning early Universe timeline. They examined data from a large group of quasars collected over two decades. By combining measurements taken at different light wavelengths, they could determine how each quasar “ticked.” Then, they compared the expected behavior of the quasars with their actual conduct. This helped them use each quasar’s ticking to track the expansion of the Universe.
“Thanks to this rich data, we were able to map out how the quasar clocks tick, revealing how space changes,” says Professor Lewis.
In the past, there were debates about whether quasars were cosmological objects or if the concept of an expanding universe or early universe timeline was genuine. But, with this new data and analysis, they discovered the quasars’ elusive tick, and they behave exactly as predicted by Einstein’s theory of relativity.
The gas between stars and galaxies was non-transparent in the early universe, and intense starlight could not penetrate it.
However, 1 billion years after the great bang, the gas was entirely transparent.
But what could be the possible reason for the gas being non-opaque?
Why Were the Galaxies in the Early Universe Not Transparent?
The explanation is that the stars in the galaxies emitted enough light to heat and ionize the gas around them, enhancing our collective understanding over hundreds of millions of years, according to new data from NASA’s James Webb Space Telescope.
The Understanding of Early Universe Cosmology:
The findings, from a research team led by Simon Lilly of ETH ZüriEach in Switzerland, are the most recent insights into the Era of Reionization, an era when the universe underwent profound changes. The universe’s gas was extremely hot and dense after the big bang.
The gas-cooled over hundreds of millions of years. The universe then pressed “repeat.” The gas grew hot and ionized again, most likely because of the birth of early stars in galaxies, and became transparent over millions of years.
How Big These Galaxies Are?
Researchers have been looking for definitive evidence to explain these shifts for a long time. The latest findings effectively lift the lid on the end of this reionization era.
Daichi Kashino, lead author of the team’s first publication from Nagoya University in Japan.
“Not only does Webb clearly show that these transparent regions are found around galaxies in the early universe, but we’ve also measured how large they are,”
He also added, emphasized, and praised the findings of the James Webb Telescope.
“We’re seeing galaxies reionize the gas around them using Webb’s data.”
In comparison to galaxies, these patches of clear gas are enormous. Just imagine a hot air balloon with a pea dangling inside.
Early Universe Timeline by Webb’s Observations
Webb’s observations suggest that these small galaxies played a role in reionization by clearing large areas of space surrounding them. These translucent “bubbles” grew larger and larger over the next hundred million years, finally combining and causing the entire cosmos to become transparent.
Stars and Their Composition
The quasar’s light was either absorbed by opaque gas or traveled freely through transparent gas as it proceeded toward us through successive regions of gas.
Webb’s data was combined with views of the center quasar from the W. M.
The Magellan Telescope at Las Campanas Observatory in Chile, the Keck Observatory in Hawaii, the European Southern Observatory’s Very Large Telescope, and others.
This was noted by Anna-Christina Eilers, lead author of another team publication.
“By illuminating gas along our line of sight, the quasar gives us extensive information about the composition and state of the gas,”
James Webb Telescope to Locate Transparent Galaxies
The researchers next used Webb to locate galaxies near this line of sight, revealing that the galaxies are generally surrounded by transparent zones with a radius of 2 million light-years.
In other words, toward the conclusion of the Reionization Era, Webb watched galaxies cleaning the space around them.
To put this in context, the area cleared by these galaxies is roughly the same as the distance between our Milky Way galaxy and its nearest neighbor, Andromeda.
What Caused Reionization of Galaxies in the Early Universe?
Researchers didn’t have this definitive evidence of what caused reionization until now -before Webb, they weren’t sure exactly what was to blame.
Now, here arises a question. How do these galaxies appear?
“They are more chaotic than those in the nearby universe,”
Jorryt Matthee, another ETH Zürich researcher and main author of the team’s second article, noted.
“Webb demonstrates that they were actively forming stars and must have emitted many supernovae.They had an exciting childhood!”
Eilers utilized Webb’s data along the way to determine that the black hole in the quasar at the heart of this field is the most massive known in the early universe, weighing 10 billion times the mass of the Sun.
“We still don’t know how quasars grew so large so early in the history of the universe,”
She also explained,
“That’s yet another puzzle to solve!”
Webb’s excellent photos also revealed no evidence that the quasar’s light had been gravitationally lensed, guaranteeing that the mass estimations are accurate.
Further Studies on Galaxies in Other Fields
The researchers will shortly begin a study on galaxies in five other fields, each of which will be anchored by a core quasar.
Webb’s findings from the first field were so evident that they couldn’t wait to discuss them.
“We expected to find a few dozen galaxies that existed during the Reionization Era, but we easily found 117,”
“Webb has exceeded all of our expectations.”
Early Universe Picture From Near Infrared Camera
Lilly’s research team, the Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization (EIGER) have demonstrated the unique power of combining conventional images from Webb’s NIRCam (Near-Infrared Camera) With data from the same instrument’s wide-field slitless spectroscopy mode gives a spectrum of every object in the images – turning Webb into what the team calls a “spectacular spectroscopic redshift machine.”
Team’s First Publications:
The team’s first publications include “EIGER I. a large sample of [O iii]-emitting galaxies at 5.3 z 6.9 and direct evidence for local reionization by galaxies,” led by Kashino,
“EIGER II. first, spectroscopic characterization of the young stars and ionized gas associated with strong H and [OIII] line-emission in galaxies at z = 5
Galaxies have evolved significantly in every aspect from the time of early galaxy formation and the present. They have continuously increased their celestial populations while enlarging the cosmic medium with heavy elements, producing multiple generations of stars from molecular gas clouds. James Webb Space Telescope (JWST) discovers that galaxies in the early universe were surprisingly diverse.
According to NASA’s observational study of thousands of galaxies. NASA found that the cosmos is significantly more diversified and developed than previously believed. The study was based on 850 galaxies that were approximately 11–13 billion years old and were spotted at redshifts of z 3–9.
Hubble Deep Field images VS JWST images!
JWST is valuable to Hubble at revealing structures in distant galaxies for two reasons: First, because of its bigger mirror, it has better light-gathering capabilities and can see farther and more clearly. Second, it can see through dust more clearly because it looks at longer infrared wavelengths than Hubble.
On December 28, 1995, 342 different types of images were merged to produce the Hubble Deep Field image. Astronomers claimed to measure the movement, age, and composition of the galaxies photographed by combining these photos.
They claimed that bluer objects may include young stars or be nearby. Older stars may be present in redder objects, or they may be further away. Even the biggest telescopes have never been able to observe most of the galaxies because they are four billion times fainter than the human eye can see.
But as for JWST discovery, Scientists and researchers are now saying that to determine a galaxy’s age and field more time is needed. As the galaxies even at the high redshifts were already quite developed.
When the images taken by James Webb Space Telescope (JWST) were compared to Hubble Space Telescope photos that depict the same dim, high redshift galaxies, JWST images are slightly clearer.
What do experts say?
A lead author of the new paper and one of the CEERS researchers Jeyhan Kartaltepe also made a statement. He says that even at high redshifts the galaxies were already quite developed. Moreover, she said that the galaxies at high redshifts also had a vast range of structures
Jeyhan Kartaltepe have said that:
“This suggests that we still don’t know when the earliest galactic structures formed,”
Moreover, Jeyhan Kartaltepe concluded:
“We have yet to see the very first galaxies with disks. We will have to study many more galaxies at even higher redshifts to quantify at what point features such as discs were able to form.”
Another researcher who was researching this problem Mr. Jordan Mirocha (Jet Propulsion Laboratory), said:
“There’s either an overabundance of galaxies, or they’re much brighter than our typical models predict,”