A huge cloud of invisible particles seems to be missing from the Milky Way

[Judi Lynn]

By Rafi Letzter - Staff Writer 13 hours ago

Scientists disagree about how to interpret a new paper with heavy implications for light dark matter.



A Hubble Space Telescope image shows the Lagoon Nebula, part of the small portion of matter in the Milky Way that isn't made of dark matter.
(Image: © NASA)

The Milky Way may be missing a strange X-ray glow long associated with dark matter in other galaxies, a new study has found. If this glowing halo is really missing — and physicists not involved in the study are highly skeptical it’s truly absent — it would deal a blow to the theory that dark matter is made up of hypothetical "sterile neutrinos." Sterile neutrinos are theoretical ghostly cousins of the faint subatomic neutrinos scientists have already discovered, and may or may not exist.

The researchers of the new study, which was published March 27 in the journal Science, looked for this glowing halo in a slightly different way from past attempts, something that is the biggest point of contention among other physicists.

"From a science perspective, I think the fact that we're getting a lot of pushback — and a lot of interest — in our work, is the way that science should be operating," said study co-author Nicholas Rodd, a University of California, Berkeley astrophysicist. "People have been thinking about how to search for these neutrinos with X-rays for some time. We came in and really had a new idea of how to look for them. And any time someone comes in and says, 'I have a new idea for how to look for something that's different from what you are doing,' your gut instinct should be skepticism. I think it is totally the natural response."

. . .

Dark matter is the biggest unknown in the universe. Scientists know it's there, primarily because they can see the effects of its gravity in galaxies; the known stars and gases aren't nearly heavy enough to bind galaxies together. So, astrophysicists believe that galaxies have unseen "halos" of dark matter providing the missing bulk, and collectively account for 85% of the mass of the universe. (There are other sorts of evidence for dark matter out there, but this is the big one.) They don't, however, know what this mystery matter is made of.

More:
https://www.livescience.com/sterile-neutrino-dark-matter-signal-missing-milky-way.html?utm_source=notification

[lastlib]

1. I didn't eat it.....