Dark energy tagged posts

NASA’s Roman Mission Gets Cosmic ‘Sneak Peek’ From Supercomputers

This graphic highlights part of a new simulation of what NASA’s Nancy Grace Roman Space Telescope could see when it launches by May 2027. The background spans about 0.11 square degrees (roughly equivalent to half of the area of sky covered by a full Moon), representing less than half the area Roman will see in a single snapshot. The inset zooms in to a region 300 times smaller, showcasing a swath of brilliant synthetic galaxies at Roman’s full resolution. Having such a realistic simulation helps scientists study the physics behind cosmic images –– both synthetic ones like these and future real ones. Researchers will use the observations for many types of science, including testing our understanding of the origin, evolution, and ultimate fate of the universe.
C. Hirata and K...
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Why is the Universe Ripping Itself Apart? A new study shows Dark Energy may be more complicated than we thought

A small star slurping material from a much larger one.
In a Type Ia supernova, a white dwarf slowly pulls mass from a neighboring star before exploding. NASA / JPL-Caltech, CC BY

What is the universe made of? This question has driven astronomers for hundreds of years.

For the past quarter of a century, scientists have believed “normal” stuff like atoms and molecules that make up you, me, Earth, and nearly everything we can see only accounts for 5% of the universe. Another 25% is “dark matter”, an unknown substance we can’t see but which we can detect through how it affects normal matter via gravity.

The remaining 70% of the cosmos is made of “dark energy”. Discovered in 1998, this is an unknown form of energy believed to be making the universe expand at an ever-increasing rate.

In a new study soon to be published in the Astronom...

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Reinventing Cosmology: New research puts Age of Universe at 26.7 — not 13.7 — billion years

Galaxy

Our universe could be twice as old as current estimates, according to a new study that challenges the dominant cosmological model and sheds new light on the so-called “impossible early galaxy problem.”

“Our newly-devised model stretches the galaxy formation time by a several billion years, making the universe 26.7 billion years old, and not 13.7 as previously estimated,” says author Rajendra Gupta, adjunct professor of physics in the Faculty of Science at the University of Ottawa.

For years, astronomers and physicists have calculated the age of our universe by measuring the time elapsed since the Big Bang and by studying the oldest stars based on the redshift of light coming from distant galaxies...

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Study using X-Ray Telescope indicates that Dark Energy is Uniformly Distributed in Space and Time

eROSITA X-Ray study indicates that dark energy is uniformly distributed in space and time
X-ray (over) and optical pseudo-color (below) images of three low mass clusters identified in the eFEDS survey data. The highest redshift cluster come from a time when the universe was approximately 10 billion years younger than today. The cluster galaxies in that case are clearly much redder than the galaxies in the other two clusters. Credit: eRosita

When Edwin Hubble observed distant galaxies in the 1920s, he made the groundbreaking discovery that the universe is expanding. It was not until 1998, however, that scientists observing Type Ia supernovae further discovered that the universe is not just expanding but has begun a phase of accelerating expansion. “To explain this acceleration, we need a source,” says Joseph Mohr, astrophysicist at LMU...

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