A new study found the possible reason why some dwarf galaxies appear to not have dark matter.
- A new paper presents a possible reason for why some dwarf galaxies appear to be missing dark matter.
- The researchers at the University of California, Riverside ran cosmological simulations to find the answers.
- They discovered some galaxies were stripped of dark matter through extreme tidal loss.
Laura Sales (seated, left) and her research group of students, including Jessica Doppel (seated, right).
Credit: UCR/Stan Lim
Scientists with the the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys spent six years creating a detailed map of more than 1 billion galaxies.
- An international team of scientists created the world's largest astronomical map in an effort to better understand dark energy.
- Dark energy is the force that's thought to be driving the expansion of the universe.
- The ultimate goal of the team is to develop a three-dimensional map of the universe, which could help scientists unravel the mysteries of dark energy.
CosmoView Episode 18: Giant Map of the Sky Sets Stage for Ambitious DESI Survey<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="da03e84376ab949535faeaf2b7ead008"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/ITjT5DHsodk?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p style="margin-left: 20px;">"For millennia humans have used maps to understand and navigate our world and put ourselves in context: we rely on maps to show us where we are, where we came from, and where we're going. Astronomical maps continue this tradition on a vast scale," the National Science Foundation's NOIRLab, which is involved in the project, wrote in a <a href="https://noirlab.edu/public/news/noirlab2103/" target="_blank">blog post</a>.</p><p style="margin-left: 20px;">"They locate us within the cosmos and tell the story of the history and fate of the Universe: it will expand forever, the expansion currently accelerating because of an unknown quantity called dark energy. Astronomical maps may help explain what this dark energy is and why it exists. Capitalizing on that possibility requires an unprecedented map — one that charts faint galaxies more uniformly and over a larger area of sky than ever before."</p>
Credit: NASA/STSci/Ann Feild<p>The vast amounts of data collected by the DESI Legacy Imaging Surveys has already led to significant scientific discoveries, including some of the <a href="https://noirlab.edu/public/news/noirlab2020/" target="_blank">coolest brown dwarfs ever discovered</a>, active black holes in galaxies, and light-bending gravitational lenses, discovered through machine-learning algorithms.</p><p>But the new map is only the first stage in DESI's main goal: Creating a three-dimensional map of the universe. Over the next five years, scientists with DESI will use the data to measure the spectra of 35 million galaxies and 2.4 million quasars in the map. (Spectra is the intensity of light emitted over a range of energies.)</p>
DESI/Legacy Survey Sky Viewer<p>By determining these galaxies' positions and distance from Earth, the team will be able to plot them in three dimensions, and potentially help scientists learn more about arguably the biggest puzzle in cosmology.</p><p style="margin-left: 20px;">"Capturing the spectra of so many galaxies so quickly requires a high degree of automation," wrote NOIRLab. "DESI — equipped with an array of 5000 swiveling, automated robots, each toting a thin fiber-optic cable that can point at individual galaxies — is designed to measure the spectra of 5000 galaxies at a time. The results will ultimately provide new insights into the mysterious dark energy that is driving the Universe's accelerating expansion."</p>
Dr. Katie Mack explains what dark energy is and two ways it could one day destroy the universe.
- The universe is expanding faster and faster. Whether this acceleration will end in a Big Rip or will reverse and contract into a Big Crunch is not yet understood, and neither is the invisible force causing that expansion: dark energy.
- Physicist Dr. Katie Mack explains the difference between dark matter, dark energy, and phantom dark energy, and shares what scientists think the mysterious force is, its effect on space, and how, billions of years from now, it could cause peak cosmic destruction.
- The Big Rip seems more probable than a Big Crunch at this point in time, but scientists still have much to learn before they can determine the ultimate fate of the universe. "If we figure out what [dark energy is] doing, if we figure out what it's made of, how it's going to change in the future, then we will have a much better idea for how the universe will end," says Mack.
A new study proposes mysterious axions may be found in X-rays coming from a cluster of neutron stars.
Are Axions Dark Matter?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="5e35ce24a5b17102bfce5ae6aecc7c14"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/e7yXqF32Yvw?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Baby universes led to black holes and dark matter, proposes a new study.
- Researchers recently used a huge telescope in Hawaii to study primordial black holes.
- These black holes might have formed in the early days from baby universes and may be responsible for dark matter.
- The study also raises the possibility that our own universe may look like a black hole to outside observers.
Hyper Suprime-Cam (HSC) is a gigantic digital camera on the Subaru Telescope
Credit: HSC project / NAOJ