dark matter tagged posts

Largest-ever Map of Universe’s Active Supermassive Black Holes Released

Largest-ever map of universe's active supermassive black holes released
An infographic explaining the creation of a new map of around 1.3 million quasars from across the visible universe. Credit: ESA/Gaia/DPAC; Lucy Reading-Ikkanda/Simons Foundation; K. Storey-Fisher et al. 2024

Astronomers have charted the largest-ever volume of the universe with a new map of active supermassive black holes living at the centers of galaxies. Called quasars, the gas-gobbling black holes are, ironically, some of the universe’s brightest objects.

The new map logs the location of about 1.3 million quasars in space and time, the furthest of which shone bright when the universe was only 1.5 billion years old. (For comparison, the universe is now 13.7 billion years old.)

“This quasar catalog is different from all previous catalogs in that it gives us a three-dimensional ma...

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Astronomers Observe the Effect of Dark Matter on the Evolution of the Galaxies

Astronomers observe the effect of dark matter on the evolution of the galaxies
Image of a galaxy showing, on the left, its stellar component, and on the right (in negative), the dark matter present in its halo. Credit: Gabriel Pérez Díaz, SMM (IAC) / The EAGLE team

Dark matter comprises around 85% of all the matter in the universe. Although ordinary matter absorbs, reflects and emits light, dark matter cannot be seen directly, which makes its detection difficult. Its existence is inferred from its gravitational effects on visible matter, the material that forms stars, planets, and other objects in the cosmos.

Galaxies are made up of these two types of material The dark matter is distributed in halos, which are huge structures surrounding galaxies, while the ordinary matter is mainly present in the central regions where most of the stars are found.

Traditi...

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Stars Travel More Slowly at Milky Way’s Edge

Physicists discovered stars near the edge of the Milky Way travel more slowly than those closer to its center — a surprise suggesting our galaxy’s gravitational core may have less dark matter than previously thought.

By clocking the speed of stars throughout the Milky Way galaxy, MIT physicists have found that stars further out in the galactic disk are traveling more slowly than expected compared to stars that are closer to the galaxy’s center. The findings raise a surprising possibility: The Milky Way’s gravitational core may be lighter in mass, and contain less dark matter, than previously thought.

The new results are based on the team’s analysis of data taken by the Gaia and APOGEE instruments...

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Magnetic Fields in the Cosmos: Dark Matter could help us Discover their Origin

Magnetic fields in the Cosmos: dark matter could help us discover their origin
In the study, researchers showed that if magnetic fields are indeed primordial then it could cause an increase in dark matter density perturbations on small scales. The ultimate effect of this process would be the formation of mini-halos of dark matter, which, if detected, would hint towards a primordial nature of magnetic fields. Credit: Lucie Chrastecka

The mini-halos of dark matter scattered throughout the Cosmos could function as highly sensitive probes of primordial magnetic fields. This is what emerges from a theoretical study conducted by SISSA and published in Physical Review Letters. Present on immense scales, magnetic fields are found everywhere in the Universe. However, their origin are still subjects of debate among scholars...

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