gravitational lensing

The Dark Energy Survey collaboration has created the largest ever maps of the distribution and shapes of galaxies, tracing both ordinary and dark matter in the universe out to a distance of over 7 billion light years. The analysis, which includes the first three years of data from the survey, is consistent with predictions from the current best model of the universe, the standard cosmological model. Nevertheless, there remain hints from DES and other experiments that matter in the current universe is a few percent less clumpy than predicted.

From UChicago News, Feb. 12, 2021: Fermilab scientist Yuanyuan Zhang discusses the implications of the studies she led on intracluster light using Dark Energy Survey data, which may include a new way of measuring dark matter.

From Universe Today, Feb. 3, 2021: Recent published results from the Dark Energy Survey point to intracluster light — feeble light from rogue stars that don’t belong to a galaxy — as a potential pathway to measure dark matter. Fermilab scientist Yuanyuan Zhang contextualizes the findings.

From Super Interessante, Jan. 31, 2021: A team of researchers from Fermilab and the National Observatory in Brazil used the light of solitary stars to calculate the mass of some of the largest structures in the cosmos — galaxy clusters. In addition to taking the most detailed measurement ever published of intracluster light, the team’s new method of measurement can help further investigate dark matter.

From Physics World, March 24, 2020: Scientists using the first year of data from the Dark Energy Survey, which is led by Fermilab, establish that there is a correlation between the positions of gravitational lenses — deduced from the stretching of distant galaxies — and gamma-ray photons. A data comparison from gravitational lensing and gamma-ray observations reveals that regions of the sky with greater concentrations of matter emit more gamma rays.

From UChicago News, Feb. 6, 2020: Fermilab and University of Chicago scientist Brad Benson and colleagues use a different method to calculate the masses of distant galaxies: the polarization, or orientation, of the light left over from the moments after the Big Bang. In doing so, they demonstrate how to “weigh” galaxy clusters using light from the earliest moments of the universe — a new method that could help shed light on dark matter, dark energy and other mysteries of the cosmos.

For the first time, a team of scientists has used the orientation of light left over from the early universe to detect gravitational lensing from galaxy clusters – the bending of light around these massive objects. Using gravitational lensing data taken by the South Pole Telescope and the Dark Energy Camera, Fermilab scientist Brad Benson and colleagues have demonstrated a new way to “weigh” galaxy clusters and ultimately shed light on dark matter, dark energy and other mysteries of the cosmos.

Predicted by Einstein and discovered in 1979, gravitational lensing helps astrophysicists understand the evolving shape of the universe.