Dark Matter Archives

March 11, 2021March 11, 2021 by Brian Koberlein

What's the Connection Between Stellar-Mass Black Holes and Dark Matter?

Artist view of a black hole in the middle of solar system. Credit: Petr Kratochvil/PublicDomainPictures CC0

Imagine you are a neutron star. You’re happily floating in space, too old to fuse nuclei in your core anymore, but the quantum pressure of your neutrons and quarks easily keeps you from collapsing under your own weight. You look forward to a long stellar retirement of gradually cooling down. Then one day you are struck by a tiny black hole. This black hole only has the mass of an asteroid, but it causes you to become unstable. Gravity crushes you as the black hole consumes you from the inside out. Before you know it, you’ve become a black hole.

February 9, 2021February 9, 2021 by Brian Koberlein

If Dark Matter is Made of Sterile Neutrinos, a new Survey has Narrowed Down What to Look for

We don’t know what dark matter is. We do know what it isn’t, and that’s a problem. Matter is made of elementary particles, from the quarks and electrons that make up atoms and molecules, to primordial neutrinos spread throughout the cosmos. But none of the known elementary particles can comprise dark matter, so what is it?

February 4, 2021February 6, 2021 by Paul M. Sutter

Narrowing Down the Mass of Dark Matter

A section of the virtual universe, a billion light years across, showing how dark matter is distributed in space, with dark matter halos the yellow clumps, interconnected by dark filaments. Cosmic void, shown as the white areas, are the lowest density regions in the Universe. Credit: Joachim Stadel, UZH

Most of the matter of the universe is of a form unknown to physics. While we don’t know what the identity of the dark matter is, a new insight provided by quantum gravity is helping to drastically narrow down its mass.

February 3, 2021February 6, 2021 by Paul M. Sutter

By Measuring Light From Individual Stars Between Galaxy Clusters, Astronomers Find Clues About Dark Matter

dark matter shown in blue — This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster MACS J0416. This is one of six clusters that was studied by the Hubble Frontier Fields programme, which yielded the deepest images of gravitational lensing ever made. Scientists used intracluster light (visible in blue) to study the distribution of dark matter within the cluster.

Astronomers have been able to measure an extremely faint glow of light within galaxy clusters, and that measurement came with a surprise: it traced the amount of invisible dark matter, something that scientists have been trying to pin down for decades.

January 25, 2021January 25, 2021 by Paul M. Sutter

Astronomers Hoped to see Evidence of Dark Matter Particles Inside Betelgeuse. No Luck

An artist's impression of Betelgeuse. Its surface is covered by large star spots, which reduce its brightness. During their pulsations, such stars regularly release gas into their surroundings, which condenses into dust. Image Credit: MPIA graphics department

Axions are a hypothetical particle that might explain the existence of dark matter. But it might occasionally interact with normal matter, especially in the cores of stars. A team of physicists have searched for evidence of axions in Betelgeuse and come up with nothing. It doesn’t mean that the axion doesn’t exist, but it does mean that it will be harder to find.

December 28, 2020December 28, 2020 by Brian Koberlein

New Data Supports the Modified Gravity Explanation for Dark Matter, Much to the Surprise of the Researchers

A falling apple. Credit: Bithin raj / Unsplash

Dark matter is an extremely good theory. It’s supported by a wealth of observational and computational data, which is why it’s part of the standard model of cosmology. But dark matter hasn’t been directly observed, so sometimes even strong supporters of dark matter are motivated to look at the alternatives.

December 22, 2020December 22, 2020 by Brian Koberlein

If Axions Explain Dark Matter, it Could be Possible to Detect Them Nearby Neutron Stars

The Robert C. Byrd Green Bank Telescope. Credit: Green Bank Observatory/NRAO

As we continue to search for dark matter particles, one thing is very clear: they cannot be any of the elementary particles we’ve discovered so far. The particles would need to have mass, but interact with light only weakly. Of the known particles, neutrinos fit that description, but neutrinos have a tiny mass, and aren’t nearly enough to explain dark matter. Some other kind of particle must make up the majority of dark matter.

November 30, 2020November 30, 2020 by Paul M. Sutter

Astronomers find a galaxy that had its dark matter siphoned away

Artist rendering of possible dark matter emissions from the Milky Way. Credit: Christopher Dessert, Nicholas L. Rodd, Benjamin R. Safdi, Zosia Rostomian (Berkeley Lab)

The galaxy NGC 1052-DF4 surprised scientists by having almost no dark matter to complement its stellar population. Recently a team of astronomers has provided an explanation: a nearby galaxy has stripped NGC 1052-DF4 of its dark matter, and is currently in the process of destroying the rest of it too.

November 28, 2020November 29, 2020 by Matthew Cimone

One of These Pictures Is the Brain, the Other is the Universe. Can You Tell Which is Which?

Left: section of cerebellum, with magnification factor 40x, obtained with electron microscopy (Dr. E. Zunarelli, University Hospital of Modena); right: section of a cosmological simulation, with an extension of 300 million light-years on each side (Vazza et al. 2019 A&A).

“Science is not only compatible with spirituality; it is a profound source of spirituality. When we recognize our place in an immensity of light years and in the passage of ages, when we grasp the intricacy, beauty and subtlety of life, then that soaring feeling, that sense of elation and humility combined, is surely spiritual.” – Carl Sagan “The Demon-Haunted World.”

Learning about the Universe, I’ve felt spiritual moments, as Sagan describes them, as I better understand my connection to the wider everything. Like when I first learned that I was literally made of the ashes of the stars – the atoms in my body spread into the eternal ether by supernovae. Another spiritual moment was seeing this image for the first time:

Hippocampal mouse neuron studded with synaptic connections (yellow), courtesy Lisa Boulanger, from https://www.eurekalert.org/multimedia/pub/81261.php. The green central cell body is ? 10µm in diameter. B. Cosmic web (Springel et al., 2005). Scale bar = 31.25 Mpc/h, or 1.4 × 1024 m. Juxtaposition inspired by Lima (2009).

November 27, 2020November 27, 2020 by Paul M. Sutter

A new way to map out dark matter is 10 times more precise than the previous-best method

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

Astronomers have to be extra clever to map out the invisible dark matter in the universe. Recently, a team of researchers have improved an existing technique, making it up to ten times better at seeing in the dark.