Einstein’s theory of general relativity tells us how the curvature of space causes the path of light from a more distant galaxy to bend as the light passes near a massive cluster of galaxies. The cluster of galaxies acts as a lens, magnifying and distorting the light from the more distant galaxy. This often leads to astronomers observing multiple “lensed images” of the distant galaxy. Compared to other commonly observed galaxy clusters, MACS J0416 is more efficient at producing multiple lensed images of background galaxies¹. This means that we expect to find a higher than usual number of images for every galaxy lensed by MACS J0416.

The Massive Cluster Survey (MACS) contains a sample of more than 100 galaxy clusters, measured by the ROSAT telescope to be bright in high-energy X-ray light. The goals of the MACS survey are to categorize and better understand distant massive galaxy clusters. 

Left: The locations of Hubble’s observations of the MACS J0416 galaxy cluster (right) and the adjacent parallel field (left) are plotted over a Digitized Sky Survey (DSS) image. The blue boxes outline the regions of Hubble’s visible-light observations, and the red boxes indicate areas of Hubble’s infrared-light observations. A scale bar in the lower left corner of the image indicates the size of the image on the sky. The scale bar corresponds to approximately 1/30th the apparent width of the full moon as seen from Earth. Astronomers refer to this unit of measurement as one arcminute, denoted as 1′.
Right: Hubble’s view of the galaxy cluster is displayed using archival visible-light observations. Deeper Frontier Fields observations of MACS J0416 are ongoing.
Left Credit: Digitized Sky Survey (STScI/NASA), and Z. Levay (STScI).
Right Credit: NASA, ESA, M. Postman (STScI), and the CLASH team.
To see the final completed Frontier Fields images of MACSJ0416 and parallel field, go here.

Estimated Dates of Observations:  January-February 2014 and August-September 2014

The planned dates for Hubble observations of the Frontier Fields include observations approximately six months apart. This is the time it takes for the cameras on Hubble to swap positions so that both visible-light data and infrared-light data can be captured from the galaxy cluster field and the adjacent parallel field, as described in this post.

Galaxy Cluster Redshift:  0.396

Redshift measures the lengthening of a light wave from an object that is moving away from an observer. For example, when a galaxy is traveling away from Earth, its observed wavelength shifts toward the red end of the electromagnetic spectrum. The galaxy cluster’s cosmological redshift refers to a lengthening of a light wave caused by the expansion of the universe. Light waves emitted by a galaxy cluster stretch as they travel through the expanding universe. The greater the redshift, the farther the light has traveled to reach us.

Galaxy Cluster Distance: approximately 4 billion light-years

Galaxy Cluster Field Coordinates (R.A., Dec.): 04:16:08.9, -24:04:28.7

Parallel Field Coordinates (R.A., Dec.): 04:16:33.1, -24:06:48.7

Constellation: Eridanus

Related Hubble News:

• Frontier Fields: Hubble Goes Deep (science content reading for students & educators)
• NASA’s Great Observatories Begin Deepest Ever Probe of the Universe
• New Mass Map of a Distant Galaxy Cluster is the Most Precise Yet

Looking for Hubble data used by scientists?

• MACS J0416 – Hubble Frontier Fields Data
• MACS J0416 – Archived Hubble Data

References to science journal articles:

1:  CLASH: The enhanced lensing efficiency of the highly elongated merging cluster MACS J0416.1-2403