Researchers have actually advanced the understanding of dark matter through simulations supporting the self-interacting dark matter (SIDM) theory. This theory possibly deals with disparities in dark matter densities observed in various galaxies, presenting a difficulty to the standard cold dark matter (CDM) design and highlighting the vibrant nature of dark matter. Credit: SciTechDaily.com
Dark matter might be more dynamic than formerly believed, UC Riverside research study reports.
Thought to comprise 85% of matter in deep space, dark matter is nonluminous and its nature is not well comprehended. While regular matter soaks up, shows, and releases light, dark matter can not be seen straight, making it more difficult to find. A theory called “self-interacting dark matter,” or SIDM, proposes that dark matter particles self-interact through a dark force, highly hitting one another near the center of a galaxy.
In work released in The < period class ="glossaryLink" aria-describedby ="tt" data-cmtooltip ="<div class=glossaryItemTitle>Astrophysical Journal Letters</div><div class=glossaryItemBody>The Astrophysical Journal Letters (ApJL) is a peer-reviewed scientific journal that focuses on the rapid publication of short, significant letters and papers on all aspects of astronomy and astrophysics. It is one of the journals published by the American Astronomical Society (AAS), and is considered one of the most prestigious journals in the field.</div>" data-gt-translate-attributes ="[{"attribute":"data-cmtooltip", "format":"html"}]" tabindex ="0" function ="link" >AstrophysicalJournalLetters, a research study group led byHai -BoYu, a teacher of physics and astronomy at the University ofCalifornia,Riverside, reports that SIDM at the same time can describe 2 astrophysics puzzles in opposite extremes.
UnderstandingDarkMatterHalos andGravitational Lensing(******************** )(************ )“The first is a high-density dark matter halo in a massive elliptical galaxy,” Yu stated.“The halo was detected through observations of strong gravitational lensing, and its density is so high that it is extremely unlikely in the prevailing cold dark matter theory. The second is that dark matter halos of ultra-diffuse galaxies have extremely low densities and they are difficult to explain by the cold dark matter theory.”
A dark matter halo is the halo of undetectable matter that penetrates and surrounds a galaxy or a cluster of galaxies.Gravitational lensing occurs when light taking a trip throughout deep space from far-off galaxies gets bent around huge items.The cold dark matter, or CDM, paradigm/theory presumes dark matter particles are collisionless. As their name recommends, ultra-diffuse galaxies have very low luminosity and the circulation of their stars and gas is expanded.
Hai-Bo Yu is a theoretical physicist at UC Riverside with proficiency in the particle residential or commercial properties of dark matter. Credit: Samantha Tieu
Yu was taken part the research study by Ethan Nadler, a joint postdoctoral fellow at the Carnegie Observatories and University of Southern California, and Daneng Yang, a postdoctoral scholar at UCR.
To reveal SIDM can describe the 2 astrophysics puzzles, the group performed the very first high-resolution simulations of cosmic structure development with strong dark matter self-interactions on appropriate mass scales for the strong lensing halo and ultra-diffuse galaxies.
“These self-interactions lead to heat transfer in the halo, which diversifies the halo density in the central regions of galaxies,” Nadler stated. “In other words, some halos have higher central densities, and others have lower central densities, compared to their CDM counterparts, with details depending on the cosmic evolution history and environment of individual halos.”
Challenging the CDM Paradigm and Future Research
According to the group, the 2 puzzles posture a powerful difficulty to the basic CDM paradigm.
“CDM is challenged to explain these puzzles,” Yang stated. “SIDM is arguably the compelling candidate to reconcile the two opposite extremes. No other explanations are available in the literature. Now there is an intriguing possibility that dark matter may be more complex and vibrant than we expected.”
The research study likewise shows the power of penetrating dark matter through astrophysical observations, with the tool of computer system simulations of cosmic structure development.
“We hope our work encourages more studies in this promising research area,” Yu stated. “It will be a particularly timely development given the expected influx of data in the near future from astronomical observatories, including the James Webb Space Telescope and upcoming Rubin Observatory.”
Since around 2009, work by Yu and partners has actually assisted promote SIDM in the particle physics and astrophysics neighborhoods.
Reference: “A Self-interacting Dark Matter Solution to the Extreme Diversity of Low-mass Halo Properties” by Ethan O. Nadler, Daneng Yang and Hai-Bo Yu, 30 November 2023, The Astrophysical Journal Letters
DOI: 10.3847/2041-8213/ ad0e09
The research study was supported by the John Templeton Foundation and the U.S. Department of Energy.
