NASA and ESO astronomers have joined forces to observe RCS2 J2327-0204, one of the most massive galaxy clusters known at its distance or beyond.
The galaxy cluster RCS2 J2327-0204. Image credit: ESO / NASA / ESA / Hubble.
RCS2 J2327-0204 is an extremely massive cluster of galaxies located approximately 6 billion light-years away.
Massive objects such as RCS2 J2327-0204 have such a strong influence on their surroundings that they visibly warp the space around them. This effect is known as gravitational lensing.
In this way, they cause the light from more distant objects to be bent, distorted, and magnified, allowing us to see galaxies that would otherwise be far too distant to detect.
Gravitational lensing is one of the predictions of Albert Einstein’s theory of general relativity.
Strong lensing produces stunning images of distorted galaxies and sweeping arcs; both of which can be seen in this image.
Weak gravitational lensing, on the other hand, is more subtle, hardly seen directly in an image, and is mostly studied statistically — but it provides a way to measure the masses of cosmic objects, as in the case of this cluster.
This image of RCS2 J2327-0204 is a composite of observations from the HAWK-I instrument on ESO’s Very Large Telescope and the Advanced Camera for Surveys (ACS) instrument on the NASA/ESA Hubble Space Telescope.
It demonstrates an impressively detailed collaborative approach to studying weak lensing in the cosmos.
The astronomers found RCS2 J2327-0204 to contain the mass of two quadrillion Suns.
The diffuse blue and white image covering the picture shows a mass map. It is connected to the amount of mass thought to be contained within each region.
