The James Webb Space Telescope program aims to map the earliest structures of the universe

When the James Webb Space Telescope (JWST) – the long-awaited successor to the Hubble Space Telescope – begins operations in 2022, one of its first tasks will be to map the earliest structures of the universe. A team of nearly 50 researchers led by scientists from the Rochester Institute of Technology and the University of Texas at Austin will try to do so through the COSMOS-Webb program, the largest General Observer program selected for the first year of JWST.

During 208.6 hours of observations, the COSMOS-Webb program will conduct an ambitious exploration of half a million galaxies with multi-band, high-resolution infrared images and unseen 32,000 galaxies in medium infrared radiation. The scientists involved said that because COSMOS-Webb is a treasury program, it will quickly release data to the public, which could lead to countless other studies by other researchers.

“The scope of our program is so exciting,” said Chief Investigator Jeyhan Kartaltepe, an assistant professor at RIT’s School of Physics and Astronomy. “The first year of observing the Web will result in many new discoveries that people will want to explore in more detail in future cycles. I think COSMOS-Webb’s public legacy will be that COSMOS will be a field where the community will conduct this kind of follow-up research.”

Caitlin Casey, assistant professor and chief investigator at UT Austin, said “COSMOS-Webb can be revolutionary in ways we never dreamed of. You don’t know what treasures you can find until you use an amazing telescope like Webb to look at the sky for a long time.”

The survey will map 0.6 square degrees of sky – around an area of ​​three full moons – using JWST’s Near Infrared Camera (NIRCam) instrument, while simultaneously mapping a smaller area of ​​0.2 square degrees with a medium infrared instrument (MIRI). Through this approach, scientists hope to achieve three main goals.

The first goal focuses on the era of reionization that occurred from 400,000 to a billion years after the Big Bang. When the first stars and galaxies formed, they provided energy for the regionalization of the early universe, and this probably happened in small pockets, not all at once. COSMOS-Webb aims to map the scale of these reionization bubbles.

Another goal is to use the MIRI instrument to search for fully evolved galaxies with high redshifts that seemingly matured soon after the formation of the universe. The Hubble Space Telescope (HST) has found examples of these galaxies, challenging existing models of how the universe formed, so it is hoped to find more examples of these high redshift galaxies and study them in more detail to understand how they could have evolved so quickly.

The third primary goal uses a technique called a weak lens. Because gravity is sensitive to all types of matter, including that we cannot see, scientists can use light distortions around galaxies to estimate the amount of dark matter. Jason Rhodes, a senior researcher at NASA’s Jet Propulsion Laboratory, said COSMOS-Webb would provide important insights into how dark matter in galaxies evolved with stellar galaxy content over the ages of the universe.

“A key result of HST-COSMOS’ initial efforts more than a decade ago showed that dark matter is the cosmic scaffold on which the structures in space we see today are formed, ”Rhodes said. “COSMOS-Webb will use the larger JWST mirror to move this mapping of dark matter further in time and toward higher-resolution maps, allowing us to study how dark matter has influenced the evolution of individual galaxies from the early universe to the present day.”

COSMOS-Webb is one of only 286 general science observer programs selected from more than 1,000 proposals for the first year of telescope science, known as Cycle 1. These specific programs will provide the world astronomical community with one of the first comprehensive opportunities to explore a scientific target with Webb. NASA is currently targeting October 31, 2021 to launch JWST.

For more information on COSMOS-Webb go to https: // /jwst /science-execution /program information? id =1727.

For more information, contact Luke Auburn at 585-490-3198, [email protected] or on Twitter: @lukeauburn.


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