Showing posts with label University of Alabama. Show all posts
Showing posts with label University of Alabama. Show all posts

Thursday, April 24

Researcher proposes first-time model that replaces dark energy and dark matter in explaining nature of the universe


Dr. Richard Lieu, a physics professor at The University of Alabama in Huntsville (UAH), a part of The University of Alabama System, has published a paper in the journal Classical and Quantum Gravity that proposes a universe built on steps of multiple singularities rather than the Big Bang alone to account for the expansion of the cosmos.

The new model forgoes the need for either dark matter or dark energy as explanations for the universe's acceleration and how structures like galaxies are generated.

The researcher's work builds on an earlier model hypothesizing that gravity can exist without mass.


Wednesday, July 14

A Lurking Cosmic Cloud

In the yawning vacuum of intergalactic space, something large is lurking.

Not a galaxy, although it's of a comparable size: A vast cloud of hot, faintly glowing gas, bigger than the Milky Way, in the space between galaxies congregating in a huge cluster.

Scientists believe this cloud may have been unceremoniously stripped from a galaxy in the cluster, the first gas cloud of this kind we've ever seen. Even more surprisingly, it hasn't dissipated, but has remained clumped together for hundreds of millions of years.

This not only tells us something new about the environments inside galaxy clusters, it suggests a new way to explore and understand these colossal structures.

"This is an exciting and also a surprising discovery. It demonstrates that new surprises are always out there in astronomy, as the oldest of the natural sciences," said physicist Ming Sun of the University of Alabama in Huntsville.

Galaxy clusters are, as the name suggests, groups of galaxies that are bound together gravitationally. The galaxy cluster where our 'orphan' gas cloud was found is called Abell 1367, or the Leo Cluster, around 300 million light-years away. It contains at least 72 major galaxies, and makes up part of a larger, supercluster complex.

Such environments often have a lot going on, and astronomers like to peer into them to try and figure out how our Universe is connected. In 2017, astronomers using Japan's Subaru Telescope spotted what appeared to be a small, warm cloud in Abell 1367; since its origin was unclear, they went back with more instruments to take a closer look.  TO READ ENTIRE ARTICLE, CLICK HERE...