Recent Gaia satellite findings suggest that dwarf galaxies are transient and less influenced by dark matter than previously believed, challenging long-held assumptions about their nature and composition.
Commonly thought to be long-lived satellites of our galaxy, a new study now finds indications that most dwarf galaxies might in fact be destroyed soon after their entry into the Galactic halo. Thanks to the latest catalog from ESA’s Gaia satellite, an international team has now demonstrated that dwarf galaxies might be out of equilibrium. The study opens important questions on the standard cosmological model, particularly on the prevalence of dark matter in our nearest environment.
It has long been assumed that the dwarf galaxies around the Milky Way are ancient satellites orbiting our Galaxy for nearly 10 billion years. This required them to contain huge amounts of dark matter to protect them from the enormous tidal effects due to the gravitational pull of our galaxy. It was assumed that dark matter caused the large differences observed in the velocities of the stars within these dwarf galaxies.
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If we ever want to simulate a universe, we should probably learn to simulate even a single atomic nucleus. But it’s taken some of the most incredible ingenuity of the past half-century to figure out how that out. All so that today I can teach you how to simulate a very very small universe.
Black holes are some of the most powerful objects in the universe — and humans could devise ways to harness that power as an energy source, a new theoretical study claims.
A recent study published in the journal Physical Review D marks a significant advancement in cosmology. A team of researchers has analyzed over one million galaxies to delve into the origins of the universe’s current cosmic structures.
This study contributes to the understanding of the ΛCDM model, the standard framework for the universe, which posits the significance of cold dark matter (CDM) and dark energy (the cosmological constant, Λ).
The model theorizes that primordial fluctuations, originating at the universe’s inception, acted as catalysts for the formation of all celestial objects, including stars, galaxies, and galaxy clusters.
Dark matter is one of the most mysterious things in the universe. But right up there in the same category are black holes — massive cosmic holes that seem to suck everything into them. Now, a new research paper posits that black holes and dark matter may go hand in hand thanks to parasitic black holes living inside of stars.
I know that’s a lot to take in, and I thought the same thing when I was reading through a new paper featured in The Astrophysical Journal . The new paper suggests that black holes might be living inside stars throughout the universe, eating away at them from the inside.
It’s a terrifying thesis and one that becomes even more terrifying when you think about the possibility of a black hole being inside our sun, eating away at it until the sun eventually dies. But just how much merit is there to this claim? Could parasitic black holes really be the cause of dark matter in the universe?
Using China’s Five-hundred-meter Aperture Spherical radio Telescope (FAST), astronomers have discovered three new pulsars in an old Galactic globular cluster known as Messier 15. Two of them turned out to be long-period pulsars, while the remaining one spins so rapidly that it was classified as a millisecond pulsar. The finding was reported in a paper published Dec. 11 on the pre-print server arXiv.
Pulsars are highly magnetized, rotating neutron stars emitting a beam of electromagnetic radiation. The most rapidly rotating pulsars, with rotation periods below 30 milliseconds, are known as millisecond pulsars (MSPs). Astronomers assume that they are formed in binary systems when the initially more massive component turns into a neutron star that is then spun up due to accretion of matter from the secondary star.
Located some 35,700 light years away from the Earth, Messier 15 (also known as NGC 7078) is a core-collapsed GC with a radius of about 88 light years and an estimated mass of 560,000 solar masses. It is one of the oldest (about 12 billion years old) and most metal-poor Galactic GCs (with a metallicity of approximately −2.25), and one of the most densely packed GCs in our galaxy.
