July 24, 2021

A New Image of a Cluster of Galaxies Emerging from the Cosmic Web

An international team of astronomers, using the Green Bank Telescope at Green Bank, West Virginia, and NASA’s Chandra X-Ray Observatory, recorded an image of a massive cluster of galaxies, very close to the time when it began to emerge from the cosmic web.

The light from the cluster of galaxies known as IDCSJ1426+3508, located at what we call z=1.75, that is, somewhere around 10 billion light years away from Earth, this means that it was observed when the universe had less than 4 billion years of life. This new measurement allows astronomers to record the properties of the thin, hot gas that permeates the entire cluster at a very early time in its existence, and these have become the most accurate measurements ever made of a distant galaxy cluster.

The incredible accuracy of measuring such a distant galaxy cluster was achieved thanks to the integration of the use of the ACIS-I instrument into Chandra, which allowed astronomers to measure the density of gas in the cluster, and the MUSTANG-2 camera in GBT, which allowed astronomers to measure the pressure of the gas at different positions in the cluster. The red color in the image, located on the outside of the cluster, indicates that the gas gets hotter as the distance increases from the center, ranging from 50 to 150 million degrees Celsius.

The MUSTNAG-2 is a bolometric camera, with currently the highest mapping speed for continuous observation made at 90 GHz, with a resolution of 10”. The ACIS-I is a wide-angle X-ray camera and provides the sharpest 1” resolution images among all missions exploring the universe in X-rays.

By comparing the gas properties of the galaxy cluster with its descendants today, astronomers were able to identify the cluster’s potential evolution. It was all quite tumultuous – everywhere but in the center – with temperatures rising despite the new cold gas incorporated from the outlying regions. The cluster center has preserved its properties despite the many disturbances exerted by the tumultuous and hostile environment, indicating that a feedback mechanism is counterbalancing all disturbance.

A swallow does not make a summer and the evolution of galaxy clusters is likely to be diverse, which is why astronomers are watching, and inviting colleagues to observe other clusters emerging from the cosmic web in hopes of identifying a common pattern overview and also individual differences. Of course, astronomers are interested in how galaxy clusters evolve over time, not just from an astrophysical perspective, for example, trying to understand how heat transport occurs, but cluster evolution is a key component of capacity. to learn about cosmology from galaxy clusters.