This is the second in a series of posts introducing and providing essential facts about each of the Frontier Fields.
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.
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
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
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References to science journal articles: