The distribution of dark matter in 25 massive clusters of galaxies is being mapped by NASA scientists using data collected by the Hubble Space Telescope.
The Hubble team's Cluster Lensing and Supernova survey has so far observed six of the 25 clusters. The Hubble Space Telescope has taken a 19-hour snapshot of galaxies whose images have been warped by the presence of the baffling interstellar substance known as dark matter, residing in an intervening galactic cluster. Astronomers say the pictures show the presence of dark matter in galaxy clusters and this information could be exactly the information needed to map out the mysterious mass.
These maps are being used to test previous results that suggest that dark matter is more densely packed inside clusters than some models predict.
Taking advantage of two of Hubble’s powerful cameras, the Advanced Camera for Surveys and the Wide Field Camera 3, the CLASH survey covers a broad wavelength range, from ultraviolet to near infrared.
Astronomers need the diverse colors to estimate the distances to lensed galaxies and study them in more detail. Hubble’s unique capabilities allow astronomers to estimate distances to galaxies that are four times fainter than ground-based telescopes can see.
Galaxy clusters are perfect laboratories for studying dark matter’s gravitational effects because they are the most massive structures in the universe. Dark matter makes up the bulk of the universe’s mass, yet it can only be detected by measuring how its gravity tugs on visible matter and warps space like a fun house mirror so that the light from distant objects is distorted.