The points of light in the images above and to the right are not stars
but rather galaxies in distant galaxy clusters — the largest
gravitationally bound structures in the universe. These clusters are so
massive that they can act as gravitational lenses, bending the light
from background objects into arcs and circles. Comparisons of
observations and cosmological models reveal that we see far more
galaxies distorted into arcs than predicted, suggesting that we don’t
yet fully understand the connections between the properties of a galaxy
cluster, its ability to lens distant objects, and cosmology. In a new
article, a team led by Carter Fox (University of Michigan) studied
dozens of galaxy clusters to understand the connection between the
properties of a cluster and its lensing strength. Fox and collaborators
identified properties that correlate with the cluster’s lensing
strength, like the amount of mass concentrated near the cluster’s
brightest galaxy. The team’s results should guide the search for galaxy
clusters with strong lensing properties, helping astronomers study
galaxies in the early universe and constrain cosmological models. To
learn more about how astronomers study gravitational lensing, check out
the full article below.
Composite-color images of 20 of the galaxy clusters from the study. The
contour lines show levels of mass density (white), magnification (cyan),
and distance from the brightest galaxy in the cluster (green). Click
for the high-resolution version. [Fox et al. 2022]
Citation
“The Strongest Cluster Lenses: An Analysis of the Relation between
Strong Gravitational Lensing Strength and the Physical Properties of
Galaxy Clusters,” Carter Fox et al 2022 ApJ 928 87. doi:10.3847/1538-4357/ac5024
Source: American Astronomical Societu - AAS/Nova
