James Webb Telescope reveals where 'engine' of merging galaxies is

The James Webb Telescope has helped a team of researchers at the University of Hiroshima in Japan identify where a bright, energetic source is in IIZw096, a system of merging galaxies about 500 million light-years from us. The "engine" of the merger lies outside the main parts of the galaxies and did not appear in observations of visible light and ultraviolet light made by the Hubble Space Telescope .

In 2010, the Spitzer telescope showed that the merging system was dominated by very luminous emissions in infrared light — most galaxy mergers emit infrared light, with wavelengths longer than those of visible light. They managed to measure the energy of the source, but could not determine its exact location.

Now, with the James Webb Telescope , they've found that the source is responsible for the bulk of emissions in the middle part of the infrared spectrum, accounting for about 70% of the system's total infrared light emission. The radius of the source measures about 570 light years, which represents a small part of the merging system - this, in turn, extends for almost 65 thousand light years.

Thomas Bohn, co-author of the study, explains that this indicates that energy is trapped in a small space. "It is intriguing that this small source, far from the galactic center, dominates the system's infrared luminosity," he noted. “We want to know what feeds this source: is it a star formation explosion or a massive black hole ?” asked Hanae Inami, an assistant professor at the university.

 In addition to finding the source's "home," the researchers found 12 luminous "clusters." Some had already appeared in Hubble telescope observations, but five new structures were detected by Webb. These, specifically, are emitting mid-infrared colors that suggest new stars are forming there.

Finally, Inami noted that future spectroscopic observations of the IIZw096 system may reveal new information about the nature of dust and ionized gas, in addition to the molecular gas present in merging galaxies . "The James Webb Telescope images revealed a hidden aspect of IIZw096 and opened the door to identifying dust-hidden sources," she concluded.

The article with the results of the study was published in The Astrophysical Journal Letters.

Source: The Astrophysical Journal Letters ; Via: Hiroshima University

 1_System II ZW 96 observed by the James Webb Telescope (Image: Reproduction/ESA/Webb, NASA & CSA, L. Armus, A. Evans)

 2_The brightness of the IIZw096 system is much more detailed in the images from the James Webb telescope than in those from Spitzer (Image: Reproduction/Hanae Inami/Hiroshima University)