Credit: NASA, ESA, A. Nierenberg (JPL), and T. Treu

Each of these Hubble Space Telescope snapshots reveals four distorted images

of a background quasar and its host galaxy surrounding the central core of a

foreground massive galaxy.

The gravity of the massive foreground galaxy is acting like a magnifying

glass by warping the quasar’s light in an effect called gravitational lensing.

Quasars are extremely distant cosmic streetlights produced by active black

holes. Such quadruple images of quasars are rare because of the nearly exact

alignment needed between the foreground galaxy and background quasar.

Astronomers used the gravitational lensing effect to detect the smallest

clumps of dark matter ever found. The clumps are located along the telescope’s

line of sight to the quasars, as well as in and around the foreground lensing

galaxies.

The presence of the dark matter concentrations alters the apparent brightness

and position of each distorted quasar image. Astronomers compared these

measurements with predictions of how the quasar images would look without the

influence of the dark matter clumps. The researchers used these measurements

to calculate the masses of the tiny dark matter concentrations.

Hubble’s Wide Field Camera 3 captured the near-infrared light from each quasar

and dispersed it into its component colors for study with spectroscopy. The

images were taken between 2015 and 2018.

Credit: NASA, ESA, A. Nierenberg (JPL), and T. Treu and D. Gilman (UCLA)

Provider: Space Telescope Science Institute

Image Source: https://hubblesite.org/contents/news-releases/2020/news-2020-05

Curator: STScI, Baltimore, MD, USA

Image Use Policy: http://hubblesite.org/copyright/