Hubble image of MACS J0717 with mass overlay: This enormous image shows Hubble’s view of massive galaxy cluster MACS J0717.5+3745. The large field of view is a combination of 18 separate Hubble images. Studying the distorting effects of gravity on light from background galaxies, a team of astronomers has uncovered the presence of a filament of dark matter extending from the core of the cluster. The location of the dark matter is revealed in a map of the mass in the cluster and surrounding region, shown here in blue. The filament visibly extends out and to the left of the cluster core. Using additional observations from ground-based telescopes, the team was able to map the filament’s structure in three dimensions, the first time this has ever been done. The filament was discovered to extend back from the cluster core, meaning we are looking along it.

Name: MACS J0717.5+3745
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Cosmology
Constellation: Auriga
Release date: 16 October 2012, 15:00
Credit: NASA, ESA, Harald Ebeling (University of Hawaii at Manoa) & Jean-Paul Kneib (LAM)

Hubble image of MACS J0717 with mass overlay: This enormous image shows Hubble’s view of massive galaxy cluster MACS J0717.5+3745. The large field of view is a combination of 18 separate Hubble images. Studying the distorting effects of gravity on light from background galaxies, a team of astronomers has uncovered the presence of a filament of dark matter extending from the core of the cluster. The location of the dark matter is revealed in a map of the mass in the cluster and surrounding region, shown here in blue. The filament visibly extends out and to the left of the cluster core. Using additional observations from ground-based telescopes, the team was able to map the filament’s structure in three dimensions, the first time this has ever been done. The filament was discovered to extend back from the cluster core, meaning we are looking along it.

Name: MACS J0717.5+3745
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Cosmology
Constellation: Auriga
Release date: 16 October 2012, 15:00
Credit: NASA, ESA, Harald Ebeling (University of Hawaii at Manoa) & Jean-Paul Kneib (LAM)

Hubble image of MACS J0717: This enormous image shows Hubble’s view of massive galaxy cluster MACS J0717.5+3745. The large field of view is a combination of 18 separate Hubble images. Studying the distorting effects of gravity on light from background galaxies, a team of astronomers has uncovered the presence of a filament of dark matter extending from the core of the cluster. This is one of the first positive detections of a filament, and the most precise to date. Using additional observations from ground-based telescopes, the team were able to map the filament’s structure in three dimensions, the first time this has ever been done.

Name: MACS J0717.5+3745
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Constellation: Auriga
Release date: 16 October 2012, 15:00
Credit: NASA, ESA, Harald Ebeling(University of Hawaii at Manoa) & Jean-Paul Kneib (LAM)

Hubble image of MACS J0717: This enormous image shows Hubble’s view of massive galaxy cluster MACS J0717.5+3745. The large field of view is a combination of 18 separate Hubble images. Studying the distorting effects of gravity on light from background galaxies, a team of astronomers has uncovered the presence of a filament of dark matter extending from the core of the cluster. This is one of the first positive detections of a filament, and the most precise to date. Using additional observations from ground-based telescopes, the team were able to map the filament’s structure in three dimensions, the first time this has ever been done.

Name: MACS J0717.5+3745
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Constellation: Auriga
Release date: 16 October 2012, 15:00
Credit: NASA, ESA, Harald Ebeling(University of Hawaii at Manoa) & Jean-Paul Kneib (LAM)

The geometry of MACS J0717: This diagram shows Hubble’s image of MACS J0717 overlaid with the location of the cluster and filament’s mass (in blue), and with a schematic of the cluster and filament (in white). Below, the diagram shows the geometry from our perspective in which the filament lies almost directly along our line of sight, and from a different perspective in which the filament is seen side-on. This shows how the filament appears greatly foreshortened from our perspective.

Name: MACS J0717.5+3745
Type: Early Universe : Galaxy : Grouping : Cluster
Category: CosmologyGalaxies
Release date: 16 October 2012, 15:00
Credit: NASA, ESA, Harald Ebeling (University of Hawaii), Karen Teramura (University of Hawaii)

Brightest galaxy in Abell 2261: The  giant elliptical galaxy in the centre of this image, taken by the  NASA/ESA Hubble Space Telescope, is the most massive and brightest  member of the galaxy cluster Abell 2261. Astronomers refer to it as the brightest cluster galaxy (BCG). Spanning a little over one million light-years, the galaxy is about 20 times the diameter of  our Milky Way galaxy. Astronomers  used Hubble's Advanced Camera for Surveys and Wide Field Camera 3 to  measure the amount of starlight across the galaxy, catalogued as 2MASX  J17222717+3207571 but more commonly called A2261-BCG (short for Abell  2261 brightest cluster galaxy). Abell 2261 is located three billion  light-years away. The  observations were taken between March and May 2011. The Abell 2261  cluster is part of a multi-wavelength survey called the Cluster Lensing  And Supernova survey with Hubble (CLASH).

Name: 2MASX J17222717+3207571, Abell 2261
Type: Local Universe : Galaxy : Grouping : ClusterEarly Universe : Galaxy : Type : Elliptical
Category: Galaxies
Constellation: Hercules
Distance: 3 billion light years
Release date: 25 October 2012, 19:00
Credit: NASA,  ESA, M. Postman (Space Telescope Science Institute, USA), T. Lauer  (National Optical Astronomy Observatory, USA), and the CLASH team.