The James Webb Telescope provides an unparalleled view of the ghostly light in galaxy clusters
In galaxy clusters, there is a fraction of stars that drift into intergalactic space as they are pulled out by the huge tidal forces created between the galaxies in the cluster. The light emitted by these stars is called intracluster light (ICL) and is extremely faint. Its brightness is less than 1% of the brightness of the darkest sky that we can observe from Earth. This is one of the reasons why images taken from space are very valuable for its analysis.
Infrared wavelengths allow us to probe galaxy clusters in a different way than visible light. Thanks to its efficiency code infrared wavelengths and the sharpness of the JWST images, IAC researchers Mireia Montes and Ignacio Trujillo were able to probe the intracluster light from SMACS-J0723.3-7327 with an unprecedented level of detail. In fact, JWST images of the center of this cluster are twice as deep as previous Hubble Space Telescope images.
“In this study, we show the great potential of JWST to observe an object that is so faint,” explains Mireia Montes, first author of the paper. “This will allow us to learn clusters of galaxies which are much further and with much more detail,” she adds.
In order to analyze this extremely faint “spooky” light, as well as the need for the observational capabilities of the new space telescope, researchers have developed new analysis techniques that improve on existing methods. “In this work, we had to perform additional processing on the JWST images to be able to study the light inside the cluster, as it is a faint and extended structure. This was crucial to avoid biases in our measurements,” says Mireia.
Thanks to the obtained data, the researchers were able to demonstrate the potential of the light inside the cluster to study and understand the processes involved in the formation of structures as massive as clusters of galaxies. “By analyzing this diffuse light, we find that the inner parts of the cluster are formed by the merger of massive galaxies, while the outer parts are caused by accretion galaxies similar to our Milky Way,” she notes.
But these observations not only offer clues about the formation of galaxy clusters, but also about the properties of a mysterious component of our universe: dark matter. The light-emitting stars within the cluster follow the cluster’s gravitational field, making this light an excellent tracer of the distribution of dark matter in these structures.
“JWST will allow us to characterize the distribution Black matter in these huge structures with unprecedented precision and shed light on its fundamental nature,” concludes Ignacio Trujillo, the second author of the article.
The paper was published in The Astrophysical Journal Letters.
Mireia Montes et al., A New Era of Intracluster Light Exploration with JWST, The Astrophysical Journal Letters (2022). DOI: 10.3847/2041-8213/ac98c5
Citation: James Webb Telescope Gives Unparalleled View of Ghostly Light in Galaxy Clusters (2022, December 2) Retrieved December 2, 2022, from https://phys.org/news/2022-12-james-webb-telescope-unparalleled-view . html
This document is subject to copyright. Except for any fair dealing for the purpose of private study or research, no part may be reproduced without written permission. The content is provided for informational purposes only.
#James #Webb #Telescope #unparalleled #view #ghostly #light #galaxy #clusters