Everything we know about the universe and all the laws of physics applies to four percent of the universe. The other 96 percent is dark matter and dark matter. Neil Degrass Tyson says, “If we calculate for all the things and energy that we are aware of, and measure how much gravity it should be, it is actually one sixth of the gravity at work in the universe. We call it the dark matter. It should really be called dark gravity. And we don’t know that. ”
Now, a new theory about the nature of dark matter as the “dark force”, about a million from Earth. Helps explain why millions of light-years pair of galaxies contain mysterious matter, according to a study by a physicist at the University of California, Riverside.
The Madden Search for Dark Matter Signals – “Where Are They Hidden?”
The dark matter is uncomfortable and cannot be seen directly. 85% of the universe is thought to create matter, its nature is not well understood. Unlike normal, it does not absorb, reflect or emit light, making it difficult to detect.
New Theory – A Dark Force
The prevailing theory of dark matter, known as cold dark matter or CDM, assumes that dark matter particles are connected to each other, with the exception of gravity. A new second theory, called self-interacting dark matter or SIDM, suggests that dark matter particles self-interact with new dark energy. Both theories explain how the overall structure of the universe emerges, but they predict the distribution of various dark matter in the interior regions of the galaxy. SIDM indicates that dark matter particles collide with each other strongly in the Milky Way’s inner halo, near its center.
Typically, a visible galaxy is organized by an invisible dark object halo – a nest-like coiled lump, which surrounds the galaxy and is held together by gravitational forces. Recent observations of two ultra-diffuse galaxies, NGC 1052-DF2 (pictured above) and NGC 1052-DF4M, show that, although this pair of galaxies is very rare, if any, dark matter, the galaxy of challenging physicists. Astrophysical observations indicate that NGC 1052-DF2 and NGC 1052-DF4 are satellite galaxies of NGC1052 (pictured above).
SIDM forms dark-matter-deficient galaxies
“It is generally believed that dark matter dominates the overall mass in a black galaxy,” said Hi-Bo Yu, an associate professor of physics and astronomy at UCR who led the study. “Observations of NGC 1052-DF2 and -DF4 show, however, that the ratio of their dark matter to the mass of their stars is 1, which is 300 times lower than expected. To address the discrepancy, we thought that DF2 and DF4 haloes could largely lose a large part of their mass by tidal exchange with the NGC 1052 Galaxy. “
“Missing” – Can Dark Matter Be a Source of Light in the Universe?
Using sophisticated simulations, the UCR-led team reproduced the properties of NGC 1052-DF2 and NGC 1052-DF4 by tidal strips – stripping the material by galactic tidal forces – by NGC 1052. Because satellite galaxies cannot keep a striped mass with their gravitational forces, it effectively joins the mass of NGC 1052.
The researchers considered both CDM and SIDM scenarios. Their results, published in Physical Review Letters, suggest that SIDMs form dark-matter-deficient galaxies such as NGC 1052-DF2 and -DF4 more than CDM, as the inner halo tidal mass loss is more significant and the distribution of stars Is more prevalent in SIDM.
“The Invisible World of Hidden Sector Particles” – Rethink Dark Matter
The UA explained that tidal losses in CDM and SIDM halls could be huge. In CDM, the internal halo structure is “rigid” and resilient to tidal bands, making it difficult for the typical CDM halo to lose enough internal mass in the tidal field to accommodate observations of NGC 1052-DF2 and -DF4. In contrast, in SIDM, dark matter self-interactions can push dark matter particles from the interior to the outer regions, making the inner halo a “fluffier” and accordingly increasing the mass loss of the tide. Next, the distribution of the stars spreads further.
“The typical CDM halo remains very wide in the interior regions even after tidal evolution,” the UA said.
Next, the team will study the NGC 1052 system more extensively and explore newly discovered galaxies with novel properties in an effort to better understand the nature of dark matter.
The research paper is entitled “Self-Interacting Dark Matter and Regions of Ultradiffused Galaxies NGC 1052-DF2 and -DF4.”
Daily Galaxy, Max Goldberg by University of California Riverside
Image at the top of the page: Shutterstock license
