Webb reveals unprecedented insight into merging galaxies
Using the James Webb Space Telescope to travel back in time to the early universe, astronomers have discovered a surprise: a cluster of galaxies merging around a rare red quasar into a massive black hole. Discoveries by Johns Hopkins University and an international team offer an unprecedented opportunity to observe how, billions of years ago, galaxies coalesced into the modern universe.
“We think something dramatic is about to happen in these systems,” said co-author Andrey Vayner, a Johns Hopkins postdoctoral fellow who studies galaxy evolution. “The galaxy is at this perfect time in its life, about to transform and look completely different in a few billion years.”
The book is in press in Astrophysical Journal Letters and Available on the arXiv paper repository.
The James Webb Space Telescope, launched last December by NASA, the European Space Agency and the Canadian Space Agency, is the largest and most powerful telescope ever sent into space. Its initial general observations were revealed in July, but this quasar imagery is one of 13 “first look” projects selected in a highly competitive global competition to decide where the telescope is pointed during its first few months of operation.
In Baltimore, the Johns Hopkins team learned that the chosen target would be observed within days of President Biden’s unveiling of the first photos of Webb on July 11, so she stayed close to their computers. The following summer’s Saturday, Vayner and graduate student Yuzo Ishikawa were repeatedly refreshing the Webb database when suddenly the data came in, leading to a hastily assembled multinational team conference on Sunday to try to make sense of the breathtakingly detailed raw images.
Although earlier observations of this area by NASA/ESA’s Hubble Space Telescope and the Gemini-North Telescope’s Near Infrared Integral Field Spectrometer instrument have identified the quasar and hinted at the possibility of a galaxy in transition, no one suspected that with Webb’s sharp imagery they would see several galaxies, at least three, swirling around the region.
“With the previous images, we thought we saw hints that the galaxy was possibly interacting with other galaxies on its way to merging because their shapes were distorted in the process and we thought we might have seen that,” said co-principal investigator Nadia L. Zakamska, a Johns Hopkins astrophysicist who helped design the project in 2017 with Dominika Wylezalek, then a postdoctoral fellow at Johns Hopkins, who is now a group leader at the University of Heidelberg. “But after I got the data from Webb, I was like, ‘I have no idea what we’re looking at here, what is all this!’ We spent several weeks watching and looking at these images.
The Webb revealed at least three incredibly fast-moving galaxies, suggesting that a large amount of mass is present. The team believe it could be one of the densest known galaxy-forming areas in the early universe.
Because light takes time to get to us, when we look at objects like this in the very distant regions of the universe, we see light that was emitted about 11.5 billions of years, or early stages in the evolution of the universe. Massive galaxy swarms like this were likely common at the time, Zakamska said.
“It’s super exciting to be one of the first people to see this really cool object,” said Ishikawa, who helped interpret the galaxy swarm.
Even Vayner, who had dreamed of using Webb’s data since he first heard about the telescope as an undergraduate student more than a decade ago and thought he knew what to expect, was shocked to see his long-studied place in the universe revealed with such clarity.
“It’s really going to transform our understanding of this object,” said Vayner, who was instrumental in adapting raw Webb data for scientific analysis.
The blindingly bright quasar, powered by what Zakamska calls a “monster” black hole at the center of the galactic vortex, is a rare “extremely red” quasar, around 11.5 billion years old and one most powerful ever seen at such a distance. It’s essentially a forming black hole, Vayner said, eating the gas around it and growing in mass. Clouds of dust and gas between Earth and glowing gas near the black hole cause the quasar to appear red.
The team is already working on follow-up observations in this unexpected galaxy cluster, hoping to better understand how dense, chaotic galaxy clusters form and how it is affected by a supermassive black hole at its core.
“What you see here is just a small subset of what’s in the dataset,” Zakamska said. “There’s too much going on here, so we’ve highlighted what’s really the biggest surprise first. Every drop here is a baby galaxy merging into this mama galaxy and the colors are at different speeds and everything is moving in different directions. an extremely complicated way. We can now begin to sort out the motions.
Other authors include: Wylezalek, Caroline Bertemes, Weizhe Liu, Jorge K. Barrera-Ballesteros, Hsiao-Wen Chen, Andy D. Goulding, Jenny E. Greene, Kevin N. Hainline, Nora Lutzgendorf, Fred Hamann, Timothy Heckman, Sean D Johnson, Dieter Lutz, Vincenzo Mainieri, Roberto Maiolino, Nicole PH Nesvadba, Patrick Ogle and Eckhard Sturm.
– This press release was provided by Johns Hopkins University