James Webb Telescope sees faint starlight from galaxy clusters
Representational image: Faint light emitted by stars that exist between galaxy clusters is called intracluster light.
| Photo Credit: AP
The powerful James Webb Telescope has captured the faint light emitted by stars that exist between galaxy clusters. The diffused light from these lone stars is called intracluster light (ICL) and helps researchers understand how galaxy clusters form.
These stars are usually found in intergalactic space as the force from surrounding galaxy clusters has flung them far away and they are no longer gravitationally bound to the galaxies they were part of. Scientists study these lights as its brightness is less than 1% of the brightness of the darkest sky that has been observed from Earth.
Researchers from the Instituto de Astrofísica de Canarias looked at a galaxy cluster called SMACS-J0723.3-7327, estimated to be 4 billion light years away from Earth. They used infrared wavelengths and the pictures taken by the James Webb Telescope (JWST) to take a deeper look into the ICL from the cluster.
The study, published by The Astrophysical Journal Letters, says that the images taken by the Webb telescope will make the study of galaxy clusters and ICL much easier as it can see twice as deep as the Hubble telescope and in much greater detail.
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Analysing the data from the ICL, the researchers found that massive galaxies merging together form the inner portions of the cluster while outer portions are formed by the accumulation of galaxies that are like the Milky Way.
ICL also offers major clues about the baffling characteristics of dark matter. According to the researchers, prevalence of dark matter can be traced through the cluster as the ICL from the isolated stars trails the gravitational field of the cluster.
Mireia Montes, author of the study said, “In this study we show the great potential of JWST for observing an object which is so faint. This will let us study galaxy clusters which are much further away, and in much greater detail.”
