Cosmology Archives

October 18, 2019October 18, 2019 by Brian Koberlein

What Was The First Color In The Universe?

The Orion Nebula, one of the most studied objects in the sky. It's likely that many of its protostars and their planetary disks contain water in some form. Image: NASA

The universe bathes in a sea of light, from the blue-white flickering of young stars to the deep red glow of hydrogen clouds. Beyond the colors seen by human eyes, there are flashes of x-rays and gamma rays, powerful bursts of radio, and the faint, ever-present glow of the cosmic microwave background. The cosmos is filled with colors seen and unseen, ancient and new. But of all these, there was one color that appeared before all the others, the first color of the universe.

September 9, 2019September 10, 2019 by Matt Williams

Gravitational Wave Detectors Might be Able to Detect Dark Matter Particles Colliding With Their Mirrors

The early universe. Credit: Tom Abel & Ralf Kaehler (KIPACSLAC)/ AMNH/NASA

The field of astronomy has been revolutionized thanks to the first-ever detection of gravitational waves (GWs). Since the initial detection was made in February of 2016 by scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO), multiple events have been detected. These have provided insight into a phenomenon that was predicted over a century ago by Albert Einstein.

As it turns out, the infrastructure that is used to detect GWs could also help crack another astronomical mystery: Dark Matter! According to a new study by a team of Japanese researchers, laser interferometers could be used to look for Weakly-Interacting Massive Particles (WIMPs), a major candidate particle in the hunt for Dark Matter.

August 12, 2019August 12, 2019 by Matt Williams

Astronomers Uncover Dozens of Previously Unknown Ancient and Massive Galaxies

The ALMA array in Chile. Once ALMA was added to the Event Horizon Telescope, it increased the EHT's power by a factor of 10. Image: ALMA (ESO/NAOJ/NRAO), O. Dessibourg

For decades, astronomers have been trying to see as far as they can into the deep Universe. By observing the cosmos as it was shortly after the Big Bang, astrophysicists and cosmologists hope to learn all they can about the early formation of the Universe and its subsequent evolution. Thanks to instruments like the Hubble Space Telescope, astronomers have been able to see parts of the Universe that were previously inaccessible.

But even the venerable Hubble is incapable of seeing all that was taking place during the early Universe. However, using the combined power of some of the newest astronomical observatories from around the world, a team of international astronomers led by Tokyo University’s Institute of Astronomy observed 39 previously-undiscovered ancient galaxies, a find that could have major implications for astronomy and cosmology.

August 7, 2019August 8, 2019 by Matt Williams

Maybe Dark Matter is Warm, Not Cold

Since the “Golden Age of General Relativity” in the 1960s, scientists have held that much of the Universe consists of a mysterious invisible mass known as “Dark Matter“. Since then, scientists have attempted to resolve this mystery with a double-pronged approach. On the one hand, astrophysicists have attempted to find a candidate particle that could account for this mass.

On the other, astrophysicists have tried to find a theoretical basis that could explain Dark Matter’s behavior. So far, the debate has centered on the question of whether it is “hot” or “cold”, with cold enjoying an edge because of its relative simplicity. However, a new study conducted led by the Harvard-Smithsonian Center for Astrophysics (CfA) revits the idea that Dark Matter might actually be “warm”.

July 22, 2019July 22, 2019 by Evan Gough

Meet Our Neighbour, The Local Void. Gaze Into It, Puny Humans.

A smoothed rendition of the structure surrounding the Local Void. Our Milky Way galaxy lies at the origin of the red-green-blue orientation arrows (each 200 million lightyears in length). We are at a boundary between a large, low density void, and the high density Virgo cluster. Credit: R. Brent Tully

Our planet is part of the larger structure of the Solar System, shaped and made stable by the force of gravity. Our Solar System is gravitationally bound to the Milky Way galaxy, along with hundreds of millions of other solar systems. And our galaxy is also part of a larger structure, where not only gravity, but the expansion of the Universe, shapes and molds that structure. For regular Universe Today readers, none of that is news.

Now a new study sheds some light on a curious part of our cosmic neighbourhood, where there is basically nothing: The Local Void.

June 10, 2019January 26, 2022 by Matt Williams

New observations from the Planck mission don’t resolve anomalies like the CMB “cold spot”

Cosmic Microwave Background. Scientists compared this to modern galaxy distributions to track dark matter. Copyright: ESA/Planck Collaboration

Back in 2013, the European Space Agency released its first analysis of the data gathered by the Planck observatory. Between 2009 and 2013, this spacecraft observed the remnants of the radiation that filled the Universe immediately after the Big Bang – the Cosmic Microwave Background (CMB) – with the highest sensitivity of any mission to date and in multiple wavelengths.

In addition to largely confirming current theories on how the Universe evolved, Planck’s first map also revealed a number of temperature anomalies – like the CMB “Cold Spot” – that are difficult to explain. Unfortunately, with the latest analysis of the mission data, the Planck Collaboration team has found no new evidence for these anomalies, which means that astrophysicists are still short of an explanation.

May 17, 2019May 17, 2019 by Paul M. Sutter

Is Dark Matter Made of Axions? Black Holes May Reveal the Answer

What is dark matter made of? It’s one of the most perplexing questions of modern astronomy. We know that dark matter is out there, since we can see its obvious gravitational influence on everything from galaxies to the evolution of the entire universe, but we don’t know what it is. Our best guess is that it’s some sort of weird new particle that doesn’t like to talk to normal matter very often (otherwise we would have seen it by now). One possibility is that it’s an exotic hypothetical kind of particle known as an axion, and a team of astronomers are using none other than black holes to try to get a glimpse into this strange new cosmic critter.

February 22, 2019February 22, 2019 by Paul M. Sutter

Meet WFIRST, The Space Telescope with the Power of 100 Hubbles

The Wide First Infrared Telescope (so far). Image credit: NASA/TJT Photography

WFIRST ain’t your grandma’s space telescope. Despite having the same size mirror as the surprisingly reliable Hubble Space Telescope, clocking in at 2.4 meters across, this puppy will pack a punch with a gigantic 300 megapixel camera, enabling it to snap a single image with an area a hundred times greater than the Hubble.

With that fantastic camera and the addition of one of the most sensitive coronagraphs ever made – letting it block out distant starlight on a star-by-star basis – this next-generation telescope will uncover some of the deepest mysteries of the cosmos.

Oh, and also find about a million exoplanets.

February 19, 2019February 19, 2019 by Evan Gough

This Star Has Been Going Nova Every Year, for Millions of Years

A nova star is like a vampire that siphons gas from its binary partner. As it does so, the gas is compressed and heated, and eventually it explodes. The remnant gas shell from that explosion expands outward and is lit up by the stars at the center of it all. Most of these novae explode about once every 10 years.

But now astrophysicists have discovered one remnant so large that the star that created it must have been erupting yearly for millions of years.

January 31, 2019January 31, 2019 by Paul M. Sutter

Uh oh, a Recent Study Suggests that Dark Energy’s Strength is Increasing

The concept of accelerating expansion does get you wondering just how much it can accelerate. Theorists think there still might be a chance of a big crunch, a steady-as-she-goes expansion or a big rip. Or maybe just a little rip?

Staring into the Darkness

The expansion of our universe is accelerating. Every single day, the distances between galaxies grows ever greater. And what’s more, that expansion rate is getting faster and faster – that’s what it means to live in a universe with accelerated expansion. This strange phenomenon is called dark energy, and was first spotted in surveys of distant supernova explosions about twenty years ago. Since then, multiple independent lines of evidence have all come to the same morose conclusion: the universe is getting fatter and fatter faster and faster.