Dark Matter Archives

February 7, 2022February 7, 2022 by Andy Tomaswick

How Dark Matter Could Be Measured in the Solar System

Dark matter has long been a mystery to astronomers, in no small part because it is so hard to measure directly. Its influence is plain when looking at its gravitational effects on objects such as far away galaxies, but measuring that influence directly has proved much trickier. But now, a team of scientists thinks they have a way to measure the influence of dark matter directly – all it would require is a specialized probe that sits really far away from Earth for a while.

January 26, 2022January 31, 2022 by Matt Williams

Finally, an Explanation for the Cold Spot in the Cosmic Microwave Background

Map of the cosmic microwave background (CMB) sky produced by the Planck satellite. The Cold Spot is shown in the inset, with coordinates and the temperature difference in the scale at the bottom. Credit: ESA/Durham University.

According to our current Cosmological models, the Universe began with a Big Bang roughly 13.8 billion years ago. During the earliest periods, the Universe was permeated by an opaque cloud of hot plasma, preventing atoms from forming. About 380,000 years later, the Universe began to cool and much of the energy generated by the Big Bang converted into light. This afterglow is now visible to astronomers as the Cosmic Microwave Background (CMB), first observed during the 1960s.

One peculiar characteristic about the CMB that attracted a lot of attention was the tiny fluctuations in temperature, which could provide information about the early Universe. In particular, there is a rather large spot in the CMB that is cooler than the surrounding afterglow, known as the CMB Cold Spot. After decades of studying the CMB’s temperature fluctuations, a team of scientists recently confirmed the existence of the largest cold spots in the CMB afterglow – the Eridanus Supervoid – might be the explanation for the CMB Cold Spot that astronomers have been looking for!

January 25, 2022January 25, 2022 by Matt Williams

Missing Mass? Not on our Watch—Dr. Paul Sutter Explains Dark Matter

Do you have a few minutes to spare and a thirst for knowledge about one of the greater mysteries of the Universe? Then head on over to ArsTechnica and check out the new series they’re releasing titled Edge of Knowledge, starring none other than Dr. Paul Sutter. In what promises to be an enlightening journey, Dr. Sutter will guide viewers through an eight-episode miniseries that explores the mysteries of the cosmos, such as black holes, the future of climate change, the origins of life, and (for their premiere episode) Dark Matter!

As far as astrophysicists and cosmologists are concerned, Dark Matter is one of the most enduring, frustrating, and confusing mysteries ever! Then, one must wonder why scientists are working so tirelessly to track it down? The short answer is: the most widely accepted theories of the Universe don’t make sense without out. The long answer is… it’s both complicated and long! Luckily, Dr. Sutter manages to sum it all up in less than 15 minutes. As an accomplished physicist, he also explains why it is so important that we track Dark Matter down!

January 23, 2022January 23, 2022 by Brian Koberlein

A Worldwide Search for Dark Matter Fails to Turn up a Signal for This Mysterious Particle

Simulation of dark matter and gas. Credit: Illustris Collaboration (CC BY-SA 4.0)

Axions are a popular candidate in the search for dark matter. There have been previous searches for these hypothetical particles, all of which have come up with nothing. But recently the results of a new search for dark matter axions have been published…and has also found nothing. Still, the study is interesting because of the nature and scale of the search.

December 24, 2021December 24, 2021 by Brian Koberlein

Primordial Black Holes Could Explain Dark Matter and the Growth of Supermassive Black Holes at the Same Time

How we might discover primordial black holes and help solve the dark matter mystery. Credit: ESA

It’s that time again. Time to look at a possible model to explain dark matter. In this case, a perennial favorite known as primordial black holes. Black holes have long been proposed as the source of dark matter. In many ways, they are the perfect candidate because they only interact with light and matter gravitationally. But stellar-mass black holes have been ruled out observationally. There simply aren’t enough of them to account for dark matter.

December 17, 2021December 15, 2021 by Paul M. Sutter

Astronomy Jargon 101: Dark Matter

This image shows the galaxy MCS J0416.1–2403, one of six clusters targeted by the Hubble Frontier Fields programme. The blue in this image is a mass map created by using new Hubble observations combined with the magnifying power of a process known as gravitational lensing. In red is the hot gas detected by NASA’s Chandra X-Ray Observatory and shows the location of the gas, dust and stars in the cluster. The matter shown in blue that is separate from the red areas detected by Chandra consists of what is known as dark matter, and which can only be detected directly by gravitational lensing.Credit: ESA/Hubble, NASA, HST Frontier Fields. Acknowledgement: Mathilde Jauzac (Durham University, UK) and Jean-Paul Kneib (École Polytechnique Fédérale de Lausanne, Switzerland).

In this series we are exploring the weird and wonderful world of astronomy jargon! You’ll feel mysterious about today’s topic: dark matter!

December 10, 2021December 10, 2021 by Matt Williams

Galaxies Have Been Found With no Dark Matter at all

This image shows the sky around the ultra diffuse galaxy NGC 1052-DF2. It was created from images forming part of the Digitized Sky Survey 2. NGC 1052-DF2 is basically invisible in this image. It is located to the southwest of the bright elliptical galaxy NGC 1052, which is dominating the field of view, and east of the bright red star HD 16873. Credit: ESA/Hubble, NASA, Digitized Sky Survey 2 Acknowledgement: Davide de Martin

One of the greatest cosmological mysteries facing astrophysicists today is Dark Matter. Since the 1960s, scientists have postulated that this invisible mass accounts for most of the matter in the Universe. While there are still many unresolved questions about it – i.e., What is it composed of? How do we detect it? What evidence is there beyond indirect detection? – we have managed to learn a few things about it over time.

For example, astrophysicists have observed that Dark Matter played a vital role in the formation of galaxies and is responsible for keeping them gravitationally bound. However, when an international team of astronomers observed the ultra-diffuse galaxy AGC 114905, they found no evidence of Dark Matter at all. If these observations are accurate, this discovery could force scientists to reevaluate their cosmological models and the way we look at the Universe.

December 6, 2021December 6, 2021 by Brian Koberlein

Maybe “Boson Clouds” Could Explain Dark Matter

Coalsack Nebula and Kappa Crucis Cluster, photo: A. Fujii — The Jewel Box is shown just right of center, above the dark nebula called the Coal Sack in this picture of the southern sky. The picture was taken with a small ground-based camera.

The nature of dark matter continues to perplex astronomers. As the search for dark matter particles continues to turn up nothing, it’s tempting to throw out the dark matter model altogether, but indirect evidence for the stuff continues to be strong. So what is it? One team has an idea, and they’ve published the results of their first search.

November 27, 2021November 27, 2021 by Brian Koberlein

Stars Getting Kicked out of the Milky Way can Help us map its Dark Matter Halo

Artist concept showing a hypervelocity star escaping our galaxy. Credit: NASA, ESA, and G. Bacon (STScI)

Dark matter is notoriously difficult to study. It’s essentially invisible to astronomers since it can’t be seen directly. So astronomers rely on effects such as the gravitational lensing of light to map its presence in the universe. That method works well for other galaxies, but not so well for our own. To map dark matter in the Milky Way, we rely mostly on the motions of stars in our galaxy. Since dark matter attracts regular matter gravitationally, the method works well for areas of the galaxy where there are stars. Unfortunately, most of the stars lie along the galactic plane, making it difficult to map dark matter above and below that plane. But a recent study proposes a way to map more of our galaxy’s dark matter using runaway stars.

November 16, 2021November 16, 2021 by Matt Williams

A new Simulation of the Universe Contains 60 Trillion Particles, the Most Ever

Illustris simulation, showing the distribution of dark matter in 350 million by 300,000 light years. Galaxies are shown as high-density white dots (left) and as normal, baryonic matter (right). Credit: Markus Haider/Illustris

Today, the greatest mysteries facing astronomers and cosmologists are the roles gravitational attraction and cosmic expansion play in the evolution of the Universe. To resolve these mysteries, astronomers and cosmologists are taking a two-pronged approach. These consist of directly observing the cosmos to observe these forces at work while attempting to find theoretical resolutions for observed behaviors – such as Dark Matter and Dark Energy.

In between these two approaches, scientists model cosmic evolution with computer simulations to see if observations align with theoretical predictions. The latest of which is AbacusSummit, a simulation suite created by the Flatiron Institute’s Center for Computational Astrophysics (CCA) and the Harvard-Smithsonian Center for Astrophysics (CfA). Capable of processing nearly 60 trillion particles, this suite is the largest cosmological simulation ever produced.