Billions of years ago, our own existence was determined by an extremely hot and dense sea of neutrons and electrons that combined to form a single atom: hydrogen. From that hydrogen, stars and galaxies began to form, and the planetary worlds began to take shape.
Astronomers have pondered the birth of the universe for centuries, but it has been difficult to determine exactly when this primordial particle soup was born.
However, an international team of researchers now believe they have obtained an accurate measurement of the age of the universe. They did this by looking at the cosmic “baby pictures”.
The research team included scientists from 41 institutions in seven countries who relied on observations from the Atacama Cosmology Telescope (ACT) in Chile. Their findings confirmed that the universe dates back 13.8 billion years ago, based on the glow left by the Big Bang.
The results were published Tuesday in the magazine. Cosmology and Non-Galactic Astrophysics.
In order to estimate the age of the universe, the researchers analyzed when it all started. They measured the oldest light emitted by the cosmos to obtain the best image of a young and small universe.
“We are restoring the ‘baby picture’ of the universe to its original condition, eliminating the wear and tear of time and space that distorted the image,” said co-author Neelima Sehgal, associate professor in the Department of Physics and Astronomy at Stony Brook University. . “Only by looking at this sharper photo or image of the baby in the universe can we better understand how our universe was born.”
The researchers relied on the cosmic microwave background, or electromagnetic radiation that has been left behind since the early years of the universe, to create this new image of the universe in its infancy.
Light, emitted 380,000 years after the Big Bang, varies in polarization; this is represented by more red or blue colors. The team used the space between these variations to calculate a new estimate of the age of the universe.
How old is the universe?
Previous estimates of the age of the universe were based on NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) and the European Space Agency’s (ESA) Planck Space Telescope.
In 2013, ESA’s Planck Telescope estimated the universe to be 13.82 billion years old according to the most detailed map ever created of the cosmic microwave background. Meanwhile, WMAP was launched in 2001 to measure the difference in temperatures in the heavens on the cosmic microwave background.
In 2016, NASA announced that the universe is 13.77 billion years old according to WMAP data.
However, in 2019, a study suggested that the universe may actually be 2 billion years younger than previously thought. That study used the motion of the stars to estimate the rate of expansion of the cosmos, and suggests that the universe has actually expanded faster than previously thought, and therefore reached its current size at a faster rate.
“Now we have found an answer where Planck and ACT agree,” said lead author Simone Aiola, a researcher at the Flatiron Institute Center for Computational Astrophysics in New York City. “It speaks to the fact that these difficult measurements are reliable.”
The new study also calculates a new measure for the Hubble constant.
The expansion rate of the universe is measured using the Hubble constant, which is calculated by comparing the distances of the galaxies with the apparent rate of recession away from Earth.
The study suggests a Hubble constant of 67.6 kilometers per second per megaparsec, which means that an object located at 1 megaparsec about 3.26 million light years from Earth is moving away from us 67.6 kilometers per second as the universe continues to expand.
Astronomers hope to use these data to further examine how the universe arose and its rate of expansion.
Summary: This document presents an algorithm for generating temperature and polarization maps that have the best characteristics of Planck and ACT: Planck’s near white noise at intermediate and large angular scales and ACT’s high resolution and sensitivity at small angular scales. We use this approach to combine data from the 2008-2018 ACT observing seasons with Planck’s complete maps to generate temperature and polarization maps that cover more than 18,000 square degrees, almost half of the entire sky, at 100, 150 and 220 GHz. Maps reveal 4,000 optically confirmed groups through the Sunyaev Zel’dovich (SZ) effect and 18,500 point source candidates at> 5σ, the largest single collection of SZ groups and millimeter wave sources to date. Multiple frequency maps provide millimeter images of nearby galaxies and individual nebulae in the Milky Way, and even clear detections of various nearby stars. Other anticipated uses of these maps include, for example, SZ thermal and kinematic SZ cluster stacking, CMB cluster lens, and galactic dust science. However, due to the preliminary nature of some of the component data sets, we caution that these maps should not be used for precision cosmological analysis. The maps will be available in LAMBDA no later than three months after the publication of this article in the magazine.
