Scientists confounded by new findings on universe’s mysterious dark matter

  • Scientists confounded by new findings on universe’s mysterious dark matter

Scientists confounded by new findings on universe’s mysterious dark matter

So, objects on the far side of that field, like distant galaxies, seem to us magnifies, duplicated, and distorted. This is if the distribution of the dark matter is slightly higher than the models predict - models of dark objects around galaxies are much smaller than the models predict.

Hubble researchers used a technique called gravitational lensing, in which distant objects are observed by looking at the way light is bent by the gravity of closer objects, with the closer objects acting like a magnifying glass.

Recently, Meneghetti led a team of astronomers to observe a massive galaxy cluster known as MACS J1206. Galaxies in the three withdrawals are examples of these effects. The red blobs around the galaxy at upper left denote emission from clouds of hydrogen in a single distant source. The source, seen four times due to the lens, might be a faint galaxy. These points were detected by the Multi-Unit Spectral Explorer (MUSE) in the Very Large Telescope (VLT) at the European Southern Observatory in Chile. The blobs do not appear in the Hubble images.

There's a problem in galaxy cluster MACS J1206, though. The Hubble image is a combination of visible- and infrared-light observations taken in 2011 by the Advanced Camera for Surveys and Wide Field Camera 3. Those involved in the study suggest that there may be problems with the model or that your understanding of dark matter may need adjustments. The final process was to compare the dark-matter maps with simulated models of galaxy clusters with similar masses at roughly the same distances. Over time, the continuous equilibrium of gravity pulled the galaxies together, forming large clusters.

The concept of dark matter was originally proposed to explain the structure of galaxies, but one of its great successes was to explain the nature of the universe itself.

Because dark matter only interacts via gravity, ignoring even electromagnetic interactions - hence why it can't be seen - gravitational lensing is now the best way to infer its presence and map the location of dark matter clusters in galaxies. The characteristic of the cosmic microwave background can be explained by the presence of dark matter.

The team of researchers is planning on gathering more data from the galaxy clusters in order to investigate their results further, and find out why it does not match up with current simulations.

The gravitational pull of cold dark matter in galaxy clusters can distort or bend the light coming from distant background galaxies, in a phenomenon called gravitational lensing. Galaxy clusters are massive repositories of dark matter owing to their tremendous gravitational influence. This is the case when the distribution of dark matter is slightly more bumpy than the model predicts. From Bologna, Italy, lead author of the study.

"We have done a lot of careful testing in comparing the simulations and data in this study, and our finding of the mismatch persists", Meneghetti continued. We don't recognize all the properties of dark matter, or something is missing from our cosmic evolution simulation.

"There's a feature of the real Universe that we are simply not capturing in our current theoretical models", Priyamvada Natarajan, a member of the research team from Yale University, told

"This could signal a gap in our current understanding of the nature of dark matter and its properties, as these exquisite data have permitted us to probe the detailed distribution of dark matter on the smallest scales", Natarajan added. Dark on the smallest scales.

The study published Friday in the journal Science. It cannot be seen directly, but its presence can only be inferred through the way it interacts with other matter that can be seen, and attempting to see its gravitational effects. The stalagmites, or peaked regions, showed the location of dark-matter halos, or subhalos in this case, associated with individual galaxies located within a cluster. The scientists mapped the dark matter within the clusters by noting how the material was warping light. Coupled with spectra from the European Southern Observatory's Very Large Telescope (VLT), the team produced an accurate, high-fidelity, dark-matter map. Inset image shows the spatial distribution of dark matter, with the spikes indicating individual galaxies.

At the moment, there's no telling what the answer is to this new part of the dark matter mystery. The researchers found a strong agreement between the appearance of lensed objects and the location of individual galaxies, which allowed them to validate their mass-distribution calculations.

An undated NASA/ESA Hubble Space Telescope image shows the massive galaxy cluster MACSJ 1206. "We were able to associate the galaxies with each cluster and estimate their distances". The hypothesized matter is thought to exist based on the mass of galaxies, but has never been directly observed. Each of these massive clusters, held together by gravity, is made up of about 1,000 individual galaxies - each of which carries its own dollop of dark matter.

The team looks forward to continuing their stress-testing of the standard dark-matter model to pin down its intriguing nature.

Future missions like the Nancy Grace Roman Space Telescope, set to launch in the mid-2020s, will use gravitational lensing of large galaxy clusters to find even more distant galaxies. Using this map, and focusing on three key clusters - MACS J1206.2-0847, MACS J0416.1-2403, and Abell S1063 - the researchers tracked the lensing distortions and from there traced out the amount of dark matter and how it is distributed. This allowed the researchers to determine which objects must be behind the galaxy cluster and, thus, potential candidates for gravitational lensing. The telescope is operated by NASA's Goddard Space Flight Center in Greenbelt, Maryland.