Established in 2020 Wednesday, April 10, 2024


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. Image courtesy: Gabriel Pérez Díaz, SMM (IAC) / The EAGLE team.



SAN CRISTÓBAL DE LA LAGUNA.- 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.

Traditionally observational studies of galactic evolution have centered on the role of ordinary matter, even though it is quite a small fraction of the mass of a galaxy. For decades there have been theoretical predictions about the effect that dark matter should have on the evolution of galaxies. However, in spite of numerous efforts, there is no clear consensus about this.

Now, research led by a team at the IAC has managed to confirm, for the first time using observations, the effect of dark matter on galaxy evolution. The work is published in the journal Nature Astronomy.

"Dark matter has an obvious effect on galaxies because we can measure it, but the effect on the evolution of galaxies which we have found is something which had been proposed, even though we did not have a technique for studying it observationally," explains Laura Scholz Díaz, a pre-doctoral researcher at the IAC and first author of the article.

To study the effect of dark matter the team has concentrated on the difference between the mass of the stars in a galaxy, and the mass which can be inferred from its rotation, called the total dynamical mass.

The research showed that the ages, the metal content, the morphology, the angular momentum and the rate of formation of the stars depend not only on the mass of those stars, but also on the total mass, and this means including the dark matter component which fits the estimates of the halo mass.

"We have seen that in galaxies with equal masses of stars, their stellar populations behave differently depending on whether the halo has more, or less dark matter, in other words, the evolution of a galaxy, from its formation until the present time is modified by the halo in which it is contained. If it has a more or a less massive halo, the evolution of the galaxy over time will be different, and this will be reflected in the properties of the stars which it contains," adds Ignacio Martín Navarro, an IAC researcher who is a co-author of the article

In the future the team plans to make measurements of stellar populations at different distances from the center of the galaxy, and to show whether this dependence on the dark matter halo of the properties of the stars is maintained at all radii. A following step in the research will allow the study of the relation between dark matter halos and the large scale structure of the universe.

"These dark matter halos are not created alone they are connected by filaments which form part of the large scale structure, called the cosmic web," says Scholz. "The mass of the halo appears to modify the property of its galaxy, but it could be the result of the position occupied by each halo within the cosmic web. In the coming years we want to see the effect of this large scale structure in the context we are studying," she explains.

This study is based on 260 galaxies of the CALIFA (Calar Alto Legacy Integral Field Area) an international project in which the IAC participates actively under the coordination of Jesús Falcón Barroso, another co-author of the article.

"This survey gives spectral information, and gives unprecedented spatial cover of galaxies," he says. "These galaxies were observed in a high resolution configuration, to obtain detailed measurements of their kinematic properties, which allowed us to study the motions of the stars very precisely, and so infer the total masses of the galaxies."







Today's News

February 24, 2024

Paleontologists discover a 240-million-year-old 'Chinese dragon'

UChicago scientists invent ultra-thin, minimally-invasive pacemaker controlled by light

Scientists closer to finding quantum gravity theory after measuring gravity on microscopic level

Neanderthals' usage of complex adhesives reveals higher cognitive abilities, scientists discover

Electrons become fractions of themselves in graphene, study finds

Scientists discover exotic quantum interference effect in a topological insulator device

Neurobiology: Examining how bats distinguish different sounds

Physicists discover a quantum state with a new type of emergent particles: Six-flux composite fermions

Astronomers find first strong evidence of neutron star remnant of exploding star

Killer instinct drove evolution of mammals' predatory ancestors, scientists suggest

Bio-inspired neuroprosthetics: sending signals the brain can understand

Snakes' rapid evolution might be the secret of their success

New tool for assessing diarrhea-related dehydration is built for global deployment

How chronic stress spreads cancer

Super strong magnetic fields leave imprint on nuclear matter

Chemical labeling method provides new approach for recording cellular activities

Study shows orchid family emerged in northern hemisphere and thrived alongside dinosaurs for 20 million years

Cracking the code of neurodegeneration: New model identifies potential therapeutic target

Researchers harness 2D magnetic materials for energy-efficient computing

Amorphous solar cells with FIDO technology are more efficient, stable and lightweight

Graphene research: Numerous products, no acute dangers

Experiment paves the way for new set of antimatter studies by laser-cooling positronium

Astronomers observe the effect of dark matter on the evolution of the galaxies

Protein integral to sperm development and male fertility identified

Redefining Identity Verification Technology in 2024



 


Editor & Publisher: Jose Villarreal
Art Director: Juan José Sepúlveda Ramírez



Tell a Friend
Dear User, please complete the form below in order to recommend the ResearchNews newsletter to someone you know.
Please complete all fields marked *.
Sending Mail
Sending Successful