The NASA/ESA Hubble Space Telescope has produced this beautiful image of a massive galaxy cluster called SDSS J1336-0331.
This image, taken with the Wide Field Camera 3 (WFC3) on board the NASA/ESA Hubble Space Telescope, shows the galaxy cluster SDSS J1336-0331. Image credit: NASA / ESA / Hubble.
Galaxy clusters are some of the largest cosmic structures that are kept together by the combined gravitational pull of its constituents.
They frequently extend over many millions of light-years and are usually grouped to the hierarchically next-higher level of structure, the so-called superclusters.
SDSS J1336-0331 is located about 2.2 billion light-years from Earth in the constellation Virgo.
It has a mass of about 7*1011 solar masses and contains hundreds of individual galaxies.
The most prominent is LEDA 1070113, a large and bright galaxy, close to the center of SDSS J1336-0331.
LEDA 1070113 was part of a study of star formation within the so-called brightest cluster galaxies (BCGs).
Typically located in the centers of their clusters, BCGs are among the most massive and luminous galaxies in the Universe.
They are generally huge elliptical galaxies and are likely to host active galactic nuclei in their cores.
The study found evidence to suggest that BCGs are fueled by cold gas from the galaxy.
It also showed that star formation in older BCGs no longer significantly contributes to the galaxy’s growth; instead, the stellar growth occurs through mergers, the collision of two galaxies.
Violent, gas-rich major mergers can trigger intense bursts of star formation in their aftermath.
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Kevin C. Cooke et al. 2016. Star formation in intermediate redshift 0.2 < z < 0.7 brightest cluster galaxies. ApJ 833, 224; doi: 10.3847/1538-4357/833/2/224
