Astrophysicists Map Invisible Universe Using Warped Galaxies to Reveal Dark Matter

Astrophysicists mapped the invisible universe by tracking subtle distortions in the shapes of far-off galaxies, showing how dark matter and energy forge cosmological objects. This technique, called weak gravitational lensing, enabled scientists to measure the distribution of matter across a vast swath of the sky. Using information from the Dark Energy Survey (designed to probe the expansion history of the universe and published open-access in a companion paper), as well as other data, they examined more than 270 million galaxies to understand the clumpiness of matter and confirm that the standard Lambda-CDM cosmology model accurately describes the universe's structure and evolution.

Expanded DECADE Survey Doubles Galaxy Measurements, Refining Cosmic Structure and Weak Lensing Analyses

According to a University of Chicago report, the Dark Energy Camera All Data Everywhere (DECADE) project expanded earlier surveys by including thousands of square degrees beyond the main survey area. These images, initially captured for other reasons, enabled researchers to more than double the number of galaxies that have had their shapes measured and helped them cross-reference previous discrepancies between weak lensing and cosmic microwave background predictions.

Studying galaxy shapes and redshifts shows mass curving light; Chihway Chang said archival images enable weak lensing without specialized surveys.

DECADE and Dark Energy Survey Map One-Third of Sky, Revealing Dark Matter and Energy Distribution

The DECADE and Dark Energy Survey data combined now cover a third of the sky, allowing us for the first time to explore details of the distribution of dark matter and dark energy. Worldwide, researchers are already using the public catalog to study dwarf galaxies and to fine-tune maps of the universe's mass.

The effort confirms cosmic structure growth matches standard cosmology, showing how dark matter and energy govern the universe and archival data.