According to our primary cosmological models, Dark matter Makes up approximately 85% of the mass in the universe.
Although repeated attempts to study this mysterious, invisible mass have not provided direct evidence, astrophysicists have been able to observe and measure its influence. Dark matter halos, Gravity lensesand the effect of general relativity on large-scale cosmic structures.
With the help of next-generation missions like ESA’s Euclid and NASA’s Nancy Grace Roman space telescopes, dark matter won’t be a mystery for long!
Then comes something like this: A massive galaxy appears to have little or no dark matter! This is precisely what a team of astronomers led by members of the Instituto Astrofisica de Canarias (IAC) observed when observing NGC 1277.
Located 240 million light-years away in the constellation Perseus, this lenticular galaxy is several times larger than the Milky Way.
This is the first time that a massive galaxy has been discovered that shows no signs of dark matter, which poses a serious challenge to our current cosmological models.
The study was conducted under the leadership of Sebastien ComoronExtragalactic Astronomer, IAC and Chair at the University of Laguna (ULL). The Archeology of Thick Discs (ArcThick) collaboration.
He was joined by researchers from the National Institute of Astrophysics, Optics and Electronics (INAOE), the National Science and Technology Council, the National Academy of Sciences of Ukraine, and the Institute of Particle and Cosmos Physics (IPARCOS). An article detailing their findings recently appeared in the journal Astronomy & Astrophysics.
According to the standard model of cosmology – aka. The Lambda is cold dark matter (ΛCDM) model – dark matter played (and still does) an intrinsic role in the formation and evolution of the universe.
In theory, this invisible mass existed shortly after the Big Bang and formed a halo that attracted neutral hydrogen gas into rotating disks. This gas was drawn into denser and denser clouds, triggering the formation of the first stars and galaxies.
Today, the DM is a major component of all massive galaxies and is evident from their rotation curves, the lenses they form, and their interactions with surrounding stars and the intergalactic medium (IGM).
However, when the team measured the mass distribution of NGC 1277, they only observed the star’s distribution. From this, they inferred that DM could not account for more than 5% of the galactic mass at the observed radius – although their observations indicated no DM. Comoron explained recently IAC press release:
„This result is inconsistent with currently accepted cosmological models, which include dark matter. To help us understand how the first galaxies formed, we decided to observe NGC 1277 with an integrated field spectrum. 0 light-years.”
In their paper, the team describes NGC 1277 as a prototypical „relic galaxy,” an extremely rare class that has not interacted with neighboring galaxies. These galaxies are believed to be remnants of giant galaxies that formed after the Big Bang.
However, the ΛCDM model predicts that at least 10% of galaxies should be as massive as NGC 1277, with a maximum of 70% for this particular category. said Co-author Anna Ferré-Mateu, researcher at IAC and ULL, has two possible explanations for this discrepancy:
„One, the gravitational interaction with the ambient medium in this galaxy group removed the dark matter. Another, when the galaxy formed from the merger of protogalactic fragments, the dark matter was ejected from the system, creating a relic galaxy.”
However, both of these explanations are not entirely satisfactory as far as the team is concerned.
In the future, the team plans to conduct observations and investigate the mystery further WHT Enhanced Area Velocity Explorer (WEAVE) on the tool William Herschel telescope (WHT), located at the Roque de los Muchachos Laboratory.
If WEAVE’s velocity measurements confirm that NGC 1277 does not contain DM, it could cast serious doubt on alternative theories such as modified Newtonian mechanics (MOND). said Trujillo:
„This discrepancy between the observations and what we expect is a puzzle, and may be a challenge to the standard model. Although dark matter in a particular galaxy may be lost, the modified law of gravity must be universal and cannot have exceptions, so a galaxy without dark matter is a negation of this type of alternative to dark matter.”
These observations may also shed some light on how large the galaxy is Supermassive black hole (SMBH), which is approximately 17 billion solar masses, or 4,250 times that of Sagittarius A* (the SMBH at the center of the Milky Way).
According to some astronomers, black holes may exist Source of DMformed from Collapse of DM haloes during the early universe. There is also the mystery of Dark Matter GalaxiesLike a curious case Faster J0139+4328These are almost entirely DM.
Next generation tasks etc Euclid And this Nancy Grace Roman Space telescopes will provide new insights by probing the expansion of the universe since the Big Bang. These observations aim to measure the influence of dark matter (and dark energy) on the largest cosmic scales.
The results of these and other studies could resolve the current debate by revealing the existence of a mysterious invisible mass, or that our understanding of gravity (as described by general relativity) should be revised.
This article was originally published Universe Today. Read on Original article.