Filling the gap between the cosmic microwave background and the first galaxy

One of the holy grails of cosmology is to look back at the earliest times of the history of the universe. Unfortunately, the first hundreds of thousands of years of space are covered in an invasive mist. So far, no one has ever seen it in the Big Bang in the past. After all, astronomers lack that universe fog by using data from the Chilean Atacama Cosmological Telescope (ACT).

The ACT measured the light first emitted in the baby universe about 380,000 years after the Big Bang. According to Consortium Director Suzanne Staggs, the measurements opened windows until the time when the first space structures began to be assembled. “We’re looking at the first steps to creating early stars and galaxies,” she said. “And we are not only looking at light and darkness, but also polarized light in high resolution. It’s a standout act of distinct factors from Planck and other early telescopes.”

The clearer data and images from the ACT can also help scientists understand when and where the first galaxy began to form. If ACT data is confirmed, they represent pictures of early babies in the universe, indicating that scientists can see galactic species only appear hundreds of thousands of years after the Big Bang.

How the action provided pictures of a baby in the universe

Stags and others from the ACT collaboration focused on very subtle variations in the density and velocity of gases in a very young space. It was a long process, according to Mark Devlin, the assistant director of ACT. “To make this new measurement, five years of exposure was required to allow the sensitive telescope to be tuned and to see the millimeter-wavelength light,” he said, noting that observation requires the support of highly sensitive detectors and computers.

This collaboration measured the polarization of light from the cosmic microwave background (CMB). It’s a faint microwave glow filling the space. It is the oldest light in the universe, representing the time when light was first able to move freely in the magnifying infant universe. Before that, the space was filled with what is called “primitive plasma.” It was too hot for the light to propagate.

So essentially everything and everything was dark. CMB is a faint glow of light that can eventually move freely. It shows small temperature variations in different regions, indicating variations in gas density and how it moves through space. Think of these variations as “species” of future stars and galaxies.

A small portion of the light from the CMB was polarized when it interacted with the early “density structures” of the infantile universe. Essentially, it vibrates in a different direction than other light. Light waves vibrate in all directions, but when they hit a surface they can move in a very specific direction.

Here, the easiest way to understand this is to wear polarized sunglasses. They block horizontal polarization waves that bounce off surfaces such as water. In space, when a light wave hits a cloud of gas, it biases it and changes its vibration direction. Polarization can reveal information about the object that redirected the light wave. In this case, it was caused when the earliest light bounced back from the density structure that existed at the time.

Dig polarized light from CMB

The ACT is not the first telescope to study this long period of universe history. For example, the Planck satellite also measured faint light from the CMB. According to team member Sigurd Naess, the ACT did better. Naess, a researcher at the University of Oslo and lead author of one of several papers related to the project, said: “This means that faint polarized signals will be visible directly.”

Polarized images obtained by ACT reveal detailed movements of hydrogen and helium gas in the early universe. “We previously could see where things were and now we’re seeing how they’re moving,” Staggs said. “Move tracked by polarization of light tells us how strong the pull of gravity is in different parts of space, just as we use tides to infer the existence of the moon.”

Images of polarization from CMB show very subtle variations in the density and velocity of gases filling the young universe. What appears to be a hazy cloud of light intensity is a region with a low density of hydrogen and helium oceans. These regions have expanded for millions of light years. Eventually, gravity pulled together the dense regions to form stars and galaxies. Their detailed appearance of such an early era in the universe helps scientists answer some difficult questions about the birth of the universe.

“Looking back at times when things were much simpler, we can piece together the stories of how our universe evolved into today’s rich and complex places,” says Joseph Henry Dunchley, professor of physics and astrophysics at Princeton University and leader in ACT analysis.

I’ll reveal more

The ACT data also contains information about other objects in space, such as the Milky Way, other galaxies, and galaxy clusters. In a sense, it tracks the evolution of the universe from the early stages to the present day. However, according to Erminia Calabrese, the lead author of one of several papers on observation of ACT, including those posted to the ARXIV preprint server, that data also points to something else.

“We have more accurately measured that the observable universe has been extended by almost 50 billion light years in every direction from us and contains 1,900 “Zetta Sands,” or about 2 trillion suns,” Calabrese said. “Mystical dark matter, and the equivalent of 1,300, are the dominant vacuum energy (also known as dark energy) of empty space. ”

New data from ACT helped scientists narrow the age of space to a much more accurate limit of 13.8 billion years. They can also help scientists understand more about how fast it is growing in modern times. These new measurements will help scientists prepare for their transition to Chile’s new Simons Observatory. Like ACT, it also focuses on the study of CMB, observing large bands of the sky at multiple frequencies.