Telescope captures the clearest image of cosmic infancy

For the first time, scientists can see not only the light and darkness of the baby universe, but also how the primitive gas moves. A collaboration between international researchers has produced the most detailed image, namely, our universe looks like 380,000 years after the Big Bang, equivalent to the current middle-aged universe.

The images, captured by the Atacama Cosmological Telescope (ACT) at the Chilean Andes High School, reveal the light that travels to Earth for more than 13 billion years. They represent the earliest cosmic time that humans can observe.

“We saw the first step in making the earliest stars and galaxies,” said Suzanne Staggs, professor of physics at Princeton ACT and Henry DeWolf Smyth. “And, we saw not only light and darkness, but also the polarization of high-resolution light. This is the decisive factor that distinguishes behavior from Planck and other early telescopes.”

This cosmic baby album provides insights to identify standard models of cosmology while excluding competitive alternatives. The findings will be presented at the annual meeting of the American Physics Association on March 19 and add an important definition to the observations proposed by the Planck Space Telescope a decade ago.

In the first few hundred thousand years of the universe, the original plasma was so hot that light could not move freely, making the universe effectively opaque. What we now think of Cosmic Microwave Background (CMB) radiation represents the first moment in cosmic history, when light cannot be avoided – essentially when the universe becomes transparent.

The new images reveal subtle changes in the density and velocity of hydrogen and helium that exist during cosmic infants, scientists explain. Polarization data are particularly valuable because it shows the detailed motion of these gases.

Neelima Sehgal, associate professor in the Department of Physics and Astronomy at Stony Brook University and a key member of the bill’s collaboration, emphasized the importance of these observations.

“With these images, we’ve reached half the sky, surpassing the previous “baby pictures” of the universe,” Sehgal said. He also led an international team to propose the next generation of CMB experiments called CMB-HD.

She added: “The sensitivity is particularly excellent in the polarization measurements of small scales and CMB light. In addition, other data sets claim tensions related to the standard model of cosmology; however, through this work, we have tested the standard model in different ways and found no evidence of any cracks.”

The contribution of the Stony Creek team is crucial to the success of the collaboration. Led by Sehgal, researchers including graduate students Mathew Madhavacheril, Dongwon Han and Amanda Macinnis have analyzed CMB for more than a decade.

Resolve cosmic disputes

In addition to providing breathtaking views of the neonatal universe, these observations help to address long-term scientific debates about the origin and evolution of the universe.

“Recalling that time, when things get simpler, we can combine stories about how the universe develops into a wealthy and complex place we find ourselves today,” explained Jo Dunkley, professor of physics and astrophysical sciences and head of ACT analysis at Princeton University of Princeton University.

One ongoing disagreement among cosmologists is the involvement of the Hubble constant—the speed of space today is getting bigger and bigger. CMB-derived measurements always indicate that the expansion rate per megapa is 67-68 kilometers per second, while measurements based on the motion of nearby galaxies show that the higher rate is 73-74 km/s/s/mpc.

The ACT team’s newly released data confirms the lower value with higher accuracy, although it is unlikely that it will completely resolve the debate.

The ability of telescopes to detect polarization in CMB light has proven to be particularly valuable. Staggs explains this meaning with an analogy: “Before we were looking at the position of things, and now we also see their movements. Just like using tides to infer the existence of the moon, the movement of light is the movement of movement tracked by the polarization of light, telling us the intensity of gravity in different parts of space.”

These polarization data reveal that sound waves that fell inwardly under the influence of gravity rippled in the early universe—similar to ripples spreading in ponds.

expect

When ACT completes observations in 2022, the study continues. Now, notice the new, more powerful Simons Observatory in the same location in Chile. Stony Brook University is an institutional partner for the new observatory, which recently received First Light and captured its initial observations.

The collaboration’s commitment to open science is evident in its data sharing approach. New ACT data is available publicly in NASA’s Lambda Archives and access Preper Pree Review articles on the ACT website and the open access platform Arxiv.org.

The research was supported by the National Science Foundation, the Department of Energy, Princeton University, the University of Pennsylvania and the Canadian Innovation Awards Foundation. The ACT program involves 160 collaborators from 65 institutions, led by Princeton University and the University of Pennsylvania.

As researchers continue to analyze photos of these cosmic babies, they want to learn more about how our universe evolved from an almost unified gas to the complex universe we live in today – a universe full of galaxies, stars, planets, and ultimately life itself.