The Lynx Arc
5.11.2003

While chasing the spectrum of a mysterious arc in a cluster of galaxies within the obscure northerly constellation Lynx, astronomers have stumbled upon the most massive and distant star-forming region ever discovered. The notably...

The Perseus Cluster s X Ray Skull
31.10.2000

This haunting image from the orbiting Chandra Observatory reveals the Perseus Cluster of Galaxies in x-rays, photons with a thousand or more times the energy of visible light. Three hundred twenty million light-years distant, the Perseus Cluster contains thousands of galaxies, but none of them are seen here.

Abell 1689 Warps Space
9.01.2003

Two billion light-years away, galaxy cluster Abell 1689 is one of the most massive objects in the Universe. In this view from the Hubble Space Telescope's Advanced Camera for Surveys, Abell...

Distortion from a Distant Cluster
23.08.2001

This stunning color deep sky view toward the constellation Pisces was made with data from a fast, sensitive, digital detector known as the Big Throughput Camera operating at Cerro Tololo Inter-American Observatory in Chile.

Galaxy Cluster in the Early Universe
26.02.2004

Long before medieval alchemists dreamed of transmuting base metals to gold, stellar furnaces in this massive cluster of galaxies - cataloged as RDCS 1252.9-2927 - had transformed light elements into heavy ones. In the false-color composite image individual cluster galaxies can be seen at optical and near-infrared wavelengths, shown in red, yellow, and green colors.

Abell 2218: A Galaxy Cluster Lens
11.01.1998

Gravity can bend light. Almost all of the bright objects in this Hubble Space Telescope image are galaxies in the cluster known as Abell 2218. The cluster is so massive and so compact that its gravity bends and focuses the light from galaxies that lie behind it.

Abell 370: Galaxy Cluster Gravitational Lens
21.09.2009

What is that strange arc? While imaging the cluster of galaxies Abell 370, astronomers had noted an unusual arc to the right of many cluster galaxies. Although curious, one initial response was to avoid commenting on the arc because nothing like it had ever been noted before.

JKCS041: The Farthest Galaxy Cluster Yet Measured
28.10.2009

What if we could see back to the beginning of the universe? We can -- since it takes the age of the universe for light to cross the universe. Peering at distant objects, therefore, tells us about how the universe used to be, even near its beginning.

Dwarf Galaxies in the Coma Cluster
31.05.2007

In visible light images, over a thousand galaxies are seen to lie within a volume about 20 million light-years across in the rich Coma Galaxy Cluster. But infrared images of the Coma Cluster have now been used to add thousands more to the Coma's galaxy count in the form of previously undiscovered dwarf galaxies.

Abell 1795: A Galaxy Cluster s Cooling Flow
8.12.2000

Throughout the Universe, galaxies tend to swarm in groups ranging from just a handful of members to casts of thousands. Astronomers have realized since the early 1970s that the larger swarms, immense clusters of galaxies millions of light-years across, are immersed within tenuous clouds of hot gas which glow strongly in x-rays.