Simulated Webb images of the quasar and the galaxy surrounding the quasar

Illustration of a quasar in the early universe. Researchers will study the galaxies that surround three bright quasars in detail for the first time with the James Webb Space Telescope. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)

Very distant active supermassive black holes are the brightest beacons in the universe. Known as quasars, these giants are surrounded by equally distant galaxies. In recent decades, researchers have embarked on a cosmic scavenger hunt and identified the three most distant quasars known in the past three years, each more than 13 billion light-years from Earth. Astronomers theorize that it may take billions of years for supermassive black holes and the galaxies that accompany them to form. How is it possible that these quasars became so gigantic, with billions of solar masses, in the first 700 million years of the universe? Once you can see beyond their glow, what do the accompanying galaxies look like? And what are their “neighborhoods” like?

These are questions that Xiaohui Fan and Jinyi Yang, both from the University of Arizona, and Eduardo Bañados, from the Max Planck Institute for Astronomy in Heidelberg, Germany, with an international team of astronomers, will address with observations taken by the James Webb Space Telescope. . “These are really valuable items,” Fan said. “We structured this program to learn everything we could think of so that our team and the astronomical community in general can explore these quasars.”

Webb’s sensitivity to infrared light, including mid-infrared wavelengths that can only be captured from space, will allow the team to observe these objects, whose light has traveled for 13 billion years and had its wavelengths. extended from ultraviolet and visible light to infrared light. . Webb has unmatched sensitivity and spatial resolution, which will reveal complex structures in these distant objects.

The team plans to observe and analyze the data on three scales: closely examining the quasars themselves, studying the stars in the surrounding host galaxies after removing the light from the quasars, and classifying nearby galaxies. “These quasars are very special objects,” explains Bañados. “That’s why we want to provide the best possible characterization of each with Webb.”

‘Zoom in and out’

Fan, Yang and Bañados are not wasting opportunities: they will use almost every instrument available on Webb to observe these quasars. First, they will refine measurements of the mass of each supermassive black hole. “The existence of these black holes defies theoretical models,” Yang said. “We want to get more accurate measurements of their masses to improve our understanding of how they formed and grew so rapidly.”

To increase the precision of existing measurements from other observatories, they will turn to spectra, data detailing an object’s physical properties, including mass and chemical composition, delivered by Webb’s Near Infrared Spectrograph (NIRSpec). This will allow the team to produce more precise masses of black holes.

Next, they will focus on revealing the galaxies behind the bright light from the quasars. They will take very deep and detailed images of each target with Webb’s near-infrared camera (NIRCam) and then use computer models to remove the light from the quasars on each one. The final processed images will give you the first views of starlight in the host galaxies. The team will also obtain spectra with the Webb Mid-Infrared Instrument (MIRI). No one can fully predict what you will learn. Were these ancient galaxies more compact? Do your stars contain more than hydrogen and helium? Webb will undoubtedly generate new insights.

The team will also obtain spectra from both quasars and their host galaxies to track how gas moves in host galaxies and determine whether active supermassive black holes are sending out hot winds that heat up the gas in the galaxies. Although no one can see a complete feedback loop in real time (it takes millions of years!), They can test what’s present with NIRSpec and start looking at the connections between quasars and their host galaxies.

They will also “zoom out” to see the galaxies near these quasars. Webb’s expansive, high-resolution observations will help the team characterize galaxies in the neighborhood using Webb’s Near Infrared Imager and Slitless Spectrograph (NIRISS) and NIRCam.