dark_matter (2)

Axions...

 

axionparticl.jpg
Image Source: Axion particle spotted in solid-state crystal, Max Planck Society, Phys.org

 

 

Topics: Cosmology, Dark Matter, Particle Physics, Quantum Mechanics, Standard Model

A team of physicists has made what might be the first-ever detection of an axion.

Axions are unconfirmed, hypothetical ultralight particles from beyond the Standard Model of particle physics, which describes the behavior of subatomic particles. Theoretical physicists first proposed the existence of axions in the 1970s in order to resolve problems in the math governing the strong force, which binds particles called quarks together. But axions have since become a popular explanation for dark matter, the mysterious substance that makes up 85% of the mass of the universe, yet emits no light.

If confirmed, it’s not yet certain whether these axions would, in fact, fix the asymmetries in the strong force. And they wouldn’t explain most of the missing mass in the universe, said Kai Martens, a physicist at the University of Tokyo who worked on the experiment. These axions, which appear to be streaming out of the sun, don’t act like the “cold dark matter” that physicists believe fills halos around galaxies. And they would be particles newly brought into being inside the sun, while the bulk of the cold dark matter out there appears to have existed unchanged for billions of years since the early universe.*

Still, it sure seems like there was a signal. It turned up in a dark underground tank of 3.5 tons (3.2 metric tons) of liquid xenon—the XENON1T experiment based at the Gran Sasso National Laboratory in Italy. At least two other physical effects could explain the XENON1T data. However, the researchers tested several theories and found that axions streaming out of our sun were the likeliest explanation for their results.

Physicists who weren’t involved in the experiment have not reviewed the data as of the announcement at 10 a.m. ET today (June 17). Reporters were briefed on the finding before the announcement, but data and paper on the find were not made available.

Live Science shared the XENON collaboration’s press release with two axion experts.

Physicists Announce Potential Dark Matter Breakthrough, Rafi Letzter, Live Science/Scientific American

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There Be Monsters...

Two views of galaxy Markarian 1216. The red image on the left shows X-ray observations conducted by NASA's Chandra X-Ray Observatory, and the yellowish image on the right is composed of optical observations taken by the Hubble Space Telescope. The brighter colors at the center of the Chandra image represent the increased density of hot gas in the galaxy's core.

 

Topics: Astronomy, Astrophysics, Cosmology, Dark Matter


X-ray observations of a peculiar galaxy deep within the constellation Hydra (the Sea Serpent) have revealed more dark matter at its core than expected.

The galaxy is almost as old as the universe itself, representatives from NASA's Chandra X-Ray Observatory said in a statement published Monday (June 3). This celestial body, Markarian 1216, went through a different evolution than typical galaxies and is home to stars that are within 10% of the age of the universe.

To study the dark matter within this compact, elliptically shaped galaxy about 295 million light- years from Earth, researchers conducted new observations with the Chandra spacecraft. Markarian 1216 is packed with more dark matter in its core than researchers expected, according to their findings published June 1.

 

Ancient Galaxy in the 'Sea Serpent' Has More Dark Matter Than Expected, Doris Elin Salazar, Space,com

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