DOE/Fermi National Accelerator Laboratory
A combination of observational data and sophisticated computer simulations have yielded advances in a field of astrophysics that has languished for half a century. The Dark Energy Survey, which is hosted by the U.S. Department of Energy s Fermi National Accelerator Laboratory, has published a burst of new results on what s called intracluster light, or ICL, a faint type of light found inside galaxy clusters.
The first burst of new, precision ICL measurements appeared in a paper published in The Astrophysical Journal in April 2019. Another appeared more recently in
Monthly Notices of the Royal Astronomical Society. In a surprise finding of the latter, DES physicists discovered new evidence that ICL might provide a new way to measure a mysterious substance called dark matter.
The Dark Energy Survey, a global collaboration including researchers at the University of Wisconsin–Madison, has released DR2, the second data release in the survey’s seven-year history. DR2 was the topic of sessions at the 237th Meeting of the American Astronomical Society, which was held virtually January 10-15.
The second data release from the Dark Energy Survey, or DES, is the culmination of over a half-decade of astronomical data collection and analysis with the ultimate goal of understanding the accelerating expansion of the universe and the phenomenon of dark energy, which is thought to be responsible for this accelerated expansion. It is one of the largest astronomical catalogs released to date. Keith Bechtol, assistant professor of physics at UW–Madison, has served as the DES Science Release co-coordinator since 2017, guiding the effort to assemble, scientifically validate, and document data releases for both cosmology analysis by the DES Collaboration and explorati
E-Mail
IMAGE: A randomly selected 3,000-year segment of the physics-based simulated catalog of earthquakes in California, created on Frontera. view more
Credit: Kevin Milner, University of Southern California
Massive earthquakes are, fortunately, rare events. But that scarcity of information blinds us in some ways to their risks, especially when it comes to determining the risk for a specific location or structure. We haven t observed most of the possible events that could cause large damage, explained Kevin Milner, a computer scientist and seismology researcher at the Southern California Earthquake Center (SCEC) at the University of Southern California. Using Southern California as an example, we haven t had a truly big earthquake since 1857 that was the last time the southern San Andreas broke into a massive magnitude 7.9 earthquake. A San Andreas earthquake could impact a much larger area than the 1994 Northridge earthquake, and other large earthquakes can o
Supercomputers Simulate 800,000 Years of California Earthquakes to Pinpoint Risks
Massive earthquakes are rare events and the scarcity of information about them can blind us to their risks, especially when it comes to determining the danger to a specific location or structure.
Scientists are now working to improve the calculations of danger by combining maps and histories of known faults with the use of supercomputers to simulate potential shaking deep into the future in California. The method is described in an article just published in the
Bulletin of the Seismological Society of America.
“People always want to know: When is the next ‘Big One’ coming,” said coauthor Bruce Shaw, a seismologist at Columbia University’s Lamont-Doherty Earth Observatory. “Chaos always gets in the way of answering that question. But what we can get at is
DOE/Fermi National Accelerator Laboratory
Shown here is the elliptical galaxy NGC 474 with star shells. Elliptical galaxies are characterized by their relatively smooth appearance as compared with spiral galaxies, one of which is to the left of NGC 474, which is oriented with South to the top and West to the left. The colorful neighboring spiral (NGC 470) has characteristic flocculent structure interwoven with dust lanes and spiral arms. NGC 474 is at a distance of about 31 megaparsecs (100 million light-years) from the sun in the constellation of Pisces. The region surrounding NGC 474 shows unusual structures characterized as tidal tails or shells of stars made up of hundreds of millions of stars. These features are likely due to recent (within the last billion years) mergers of smaller galaxies into the main body of NGC 474 or close passages of nearby galaxies, such as the NGC 470 spiral. For coordinate information, visit the NOIRLab webpage for this photo. (Photo: DES/NOIRLab