From NASA/ESA/CSA James Webb Space Telescope: “Mapping the Universe’s Earliest Structures with COSMOS-Webb”

NASA Webb Header

From NASA/ESA/CSA James Webb Space Telescope

August 18, 2021

MEDIA CONTACTS:
Ann Jenkins
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

1
About This Image
The COSMOS-Webb survey will map 0.6 square degrees of the sky—about the area of three full Moons—using the James Webb Space Telescope’s Near Infrared Camera (NIRCam) instrument, while simultaneously mapping a smaller 0.2 square degrees with the Mid Infrared Instrument (MIRI). The jagged edges of the Hubble field’s outline are due to the separate images that make up the survey field. Credits: SCIENCE: National Aeronautics Space Agency (US), European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU), Jeyhan Kartaltepe (Rochester Institute of Technology (US))[below], Caitlin Casey (The University of Texas-Austin (US))[below], Anton M. Koekemoer (Space Telescope Science Institute (US))

Summary

This ambitious program will study half a million galaxies in a field the size of three full Moons.

Peering deeply into a huge patch of sky the size of three full Moons, NASA’s James Webb Space Telescope will undertake an ambitious program to study half a million galaxies. Called COSMOS-Webb, this survey is the largest project Webb will undertake during its first year. With more than 200 hours of observing time, it will build upon previous discoveries to make advances in three particular areas of study. These include revolutionizing our understanding of the Reionization Era; looking for early, fully evolved galaxies; and learning how dark matter evolved with galaxies’ stellar content. With its rapid public release of the data, this survey will be a primary legacy dataset from Webb for scientists worldwide studying galaxies beyond the Milky Way.
______________________________________________________________________________________________________________

When NASA’s James Webb Space Telescope begins science operations in 2022, one of its first tasks will be an ambitious program to map the earliest structures in the universe. Called COSMOS-Webb, this wide and deep survey of half-a-million galaxies is the largest project Webb will undertake during its first year.

With more than 200 hours of observing time, COSMOS-Webb will survey a large patch of the sky—0.6 square degrees—with the Near-Infrared Camera (NIRCam). That’s the size of three full moons. It will simultaneously map a smaller area with the Mid-Infrared Instrument (MIRI).

“It’s a large chunk of sky, which is pretty unique to the COSMOS-Webb program. Most Webb programs are drilling very deep, like pencil-beam surveys that are studying tiny patches of sky,” explained Caitlin Casey, an assistant professor at the University of Texas at Austin and co-leader of the COSMOS-Webb program. “Because we’re covering such a large area, we can look at large-scale structures at the dawn of galaxy formation. We will also look for some of the rarest galaxies that existed early on, as well as map the large-scale dark matter distribution of galaxies out to very early times.”

(Dark matter does not absorb, reflect, or emit light, so it cannot be seen directly. We know that dark matter exists because of the effect it has on objects that we can observe.)

COSMOS-Webb will study half-a-million galaxies with multi-band, high-resolution, near-infrared imaging, and an unprecedented 32,000 galaxies in the mid-infrared. With its rapid public release of the data, this survey will be a primary legacy dataset from Webb for scientists worldwide studying galaxies beyond the Milky Way.

Building on Hubble’s Achievements

The COSMOS survey began in 2002 as a Hubble program to image a much larger patch of sky, about the area of 10 full moons. From there, the collaboration snowballed to include most of the world’s major telescopes on Earth and in space. Now COSMOS is a multi-wavelength survey that covers the entire spectrum from the X-ray through the radio.

Because of its location on the sky, the COSMOS field is accessible to observatories around the world. Located on the celestial equator, it can be studied from both the northern and southern hemispheres, resulting in a rich and diverse treasury of data.

“COSMOS has become the survey that a lot of extragalactic scientists go to in order to conduct their analyses because the data products are so widely available, and because it covers such a wide area of the sky,” said Rochester Institute of Technology’s Jeyhan Kartaltepe, assistant professor of physics and co-leader of the COSMOS-Webb program. “COSMOS-Webb is the next installment of that, where we’re using Webb to extend our coverage in the near- and mid-infrared part of the spectrum, and therefore pushing out our horizon, how far away we’re able to see.”

The ambitious COSMOS-Webb program will build upon previous discoveries to make advances in three particular areas of study, including: revolutionizing our understanding of the Reionization Era; looking for early, fully evolved galaxies; and learning how dark matter evolved with galaxies’ stellar content.

Goal 1: Revolutionizing Our Understanding of the Reionization Era.

Epoch of Reionization and first stars. Credit: California Institute of Technology (US).

Soon after the big bang, the universe was completely dark. Stars and galaxies, which bathe the cosmos in light, had not yet formed. Instead, the universe consisted of a primordial soup of neutral hydrogen and helium atoms and invisible dark matter. This is called the cosmic dark ages.

After several hundred million years, the first stars and galaxies emerged and provided energy to reionize the early universe. This energy ripped apart the hydrogen atoms that filled the universe, giving them an electric charge and ending the cosmic dark ages. This new era where the universe was flooded with light is called the Reionization Era.

The first goal of COSMOS-Webb focuses on this epoch of reionization, which took place from 400,000 to 1 billion years after the big bang. Reionization likely happened in little pockets, not all at once. COSMOS-Webb will look for bubbles showing where the first pockets of the early universe were reionized. The team aims to map the scale of these reionization bubbles.

“Hubble has done a great job of finding handfuls of these galaxies out to early times, but we need thousands more galaxies to understand the reionization process,” explained Casey.

Scientists don’t even know what kind of galaxies ushered in the Reionization Era, whether they’re very massive or relatively low-mass systems. COSMOS-Webb will have a unique ability to find very massive, rare galaxies and see what their distribution is like in large-scale structures. So, are the galaxies responsible for reionization living in the equivalent of a cosmic metropolis, or are they mostly evenly distributed across space? Only a survey the size of COSMOS-Webb can help scientists to answer this.

Goal 2: Looking for Early, Fully Evolved Galaxies.

COSMOS-Webb will search for very early, fully evolved galaxies that shut down star birth in the first 2 billion years after the big bang. Hubble has found a handful of these galaxies, which challenge existing models about how the universe formed. Scientists struggle to explain how these galaxies could have old stars and not be forming any new stars so early in the history of the universe.

With a large survey like COSMOS-Webb, the team will find many of these rare galaxies. They plan detailed studies of these galaxies to understand how they could have evolved so rapidly and turned off star formation so early.

Goal 3: Learning How Dark Matter Evolved with Galaxies’ Stellar Content.

COSMOS-Webb will give scientists insight into how dark matter in galaxies has evolved with the galaxies’ stellar content over the universe’s lifetime.

Galaxies are made of two types of matter: normal, luminous matter that we see in stars and other objects, and invisible dark matter, which is often more massive than the galaxy and can surround it in an extended halo. Those two kinds of matter are intertwined in galaxy formation and evolution. However, presently there’s not much knowledge about how the dark matter mass in the halos of galaxies formed, and how that dark matter impacts the formation of the galaxies.

COSMOS-Webb will shed light on this process by allowing scientists to directly measure these dark matter halos through “weak lensing.”

[caption id="attachment_41428" align="alignnone" width="632"] Caterpillar Project A Milky-Way-size dark-matter halo and its subhalos circled, an enormous suite of simulations . Griffen et al. 2016.

The gravity from any type of mass—whether it’s dark or luminous—can serve as a lens to “bend” the light we see from more distant galaxies. Weak lensing distorts the apparent shape of background galaxies, so when a halo is located in front of other galaxies, scientists can directly measure the mass of the halo’s dark matter.

“For the first time, we’ll be able to measure the relationship between the dark matter mass and the luminous mass of galaxies back to the first 2 billion years of cosmic time,” said team member Anton Koekemoer, a research astronomer at the Space Telescope Science Institute in Baltimore, who helped design the program’s observing strategy and is in charge of constructing all the images from the program. “That’s a crucial epoch for us to try to understand how the galaxies’ mass was first put in place, and how that’s driven by the dark matter halos. And that can then feed indirectly into our understanding of galaxy formation.”

Quickly Sharing Data with the Community

COSMOS-Webb is a Treasury program, which by definition is designed to create datasets of lasting scientific value. Treasury Programs strive to solve multiple scientific problems with a single, coherent dataset. Data taken under a Treasury Program usually has no exclusive access period, enabling immediate analysis by other researchers.

“As a Treasury Program, you are committing to quickly releasing your data and your data products to the community,” explained Kartaltepe. “We’re going to produce this community resource and make it publicly available so that the rest of the community can use it in their scientific analyses.”

Koekemoer added, “A Treasury Program commits to making publicly available all these science products so that anyone in the community, even at very small institutions, can have the same, equal access to the data products and then just do the science.”

COSMOS-Webb is a Cycle 1 General Observers program. General Observers programs were competitively selected using a dual-anonymous review system, the same system that is used to allocate time on Hubble.

From Rochester Institute of Technology (US)

James Webb Space Telescope program aims to map the earliest structures of the universe
COSMOS-Webb is slated to be the largest program in JWST’s first year of operation.

April 19, 2021
Luke Auburn
luke.auburn@rit.edu

3
RIT Assistant Professor Jeyhan Kartaltepe is the principal investigator of COSMOS-Webb, the largest General Observer program selected for James Webb Space Telescope’s first year. Credit: A. Sue Weisler.

When the James Webb Space Telescope (JWST)—the long-awaited successor to the Hubble Space Telescope—becomes operational in 2022, one of its first orders of business will be mapping the earliest structures of the universe. A team of nearly 50 researchers led by scientists at Rochester Institute of Technology and University of Texas at Austin will attempt to do so through the COSMOS-Webb program, the largest General Observer program selected for JWST’s first year.

Over the course of 208.6 observing hours, the COSMOS-Webb program will conduct an ambitious survey of half a million galaxies with multi-band, high-resolution near infrared imaging and an unprecedented 32,000 galaxies in mid infrared. The scientists involved said that because COSMOS-Webb is a treasury program, they will rapidly release data to the public so it can lead to countless other studies by other researchers.

“The sheer scope of our program is so exciting,” said principal investigator Jeyhan Kartaltepe, an assistant professor in RIT’s School of Physics and Astronomy. “The first year of Webb observations will result in a lot of new discoveries that people will want explore more in-depth in future cycles. I think the public legacy of COSMOS-Webb will be that COSMOS will be the field where the community conducts this type of follow-up research.”

Caitlin Casey, an assistant professor and principal investigator at UT Austin, said “COSMOS-Webb has the potential to be ground-breaking in ways we haven’t even dreamt yet. You don’t know what treasures are there to find until you use an incredible telescope like Webb to stare at the sky for a long time.”

The survey will map 0.6 square degrees of the sky—about the 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 the Mid Infrared Instrument (MIRI). Through this approach, the scientists hope to achieve three main goals [above].

“A key result from the original HST-COSMOS effort over a decade ago was showing that dark matter is the cosmic scaffolding upon which the structures in the universe we see today are formed,” said Rhodes. “COSMOS-Webb will make use of the JWST’s larger mirror to push that dark matter mapping farther in time and to higher resolution maps, allowing us to study how dark matter has influenced the evolution of individual galaxies from the early universe to now.”

COSMOS-Webb is one of just 286 General Scientific Observer programs selected out of more than 1,000 proposals for the telescope’s first year of science, known as Cycle 1. These specific programs will provide the worldwide astronomical community with one of the first extensive opportunities to investigate scientific targets with Webb. NASA is currently targeting Oct. 31, 2021, for JWST’s launch.

For more information about COSMOS-Webb, go to the Space Telescope Science Institute website.

From University of Texas-Austin (US)

20 April 2021
Rebecca A Johnson

Texas Astronomers Lead Major Projects in James Webb Space Telescope’s First Year

4
Caitlin Casey

Astronomers at The University of Texas at Austin are set to lead some of the largest programs in the first year of NASA’s James Webb Space Telescope (JWST), including the largest project overall. Set to launch this Halloween, the telescope will become operational by mid-2022. Altogether, UT astronomers received about 500 hours of telescope time in JWST’s first year.

COSMOS-Webb, a project to map the earliest structures of the universe, is the largest project JWST will undertake in 2022. UT’s Caitlin Casey, assistant professor of astronomy, leads an international team of nearly 50 researchers, along with co-leader Jeyhan Kartaltepe of the Rochester Institute of Technology.

With more than 200 hours of observing time, COSMOS-Webb will conduct an ambitious survey of half a million galaxies. As a “treasury program,” the team will rapidly release their data to the public for use by other researchers.

Casey explained that their project will “stare deeply over a large patch of sky, about three times the size of the Moon. Instead of just finding the most distant galaxies, we hope to find them and figure out where they live in the universe, whether it be an ancient cosmic metropolis or a distant cosmic outpost.”

In probing the galaxies’ habitats, they are looking for bubbles showing where the first pockets of the early universe were reionized — that is, when light from the first stars and galaxies ripped apart hydrogen atoms that filled the cosmos, giving them an electric charge. This ended the cosmic dark ages, and began a new era where the universe was flooded with light, called the epoch of reionization. COSMOS-Webb hopes to map the scale of these reionization bubbles.

“COSMOS-Webb has the potential to be ground-breaking in ways we haven’t even dreamt yet,” Casey said. “You don’t know what treasures are there to find until you use an incredible telescope like Webb to stare at the sky for a long time.”

Another major first-year JWST project is led by UT associate professor Steven Finkelstein. The fourth-largest project the telescope will undertake in 2022, it’s called the Webb Deep Extragalactic Exploratory Public (WDEEP) Survey. Finkelstein co-leads a large team along with Casey Papovich of Texas A&M University and Nor Pirzkal of the Space Telescope Science Institute.

In some ways, WDEEP is similar to COSMOS-Webb, Finkelstein said. Both are studying early galaxies, but at different early epochs in the history of the universe.

“Together, the projects COSMOS-Webb and WDEEP are bracketing the epoch of reionization,” Finkelstein said. “So with WDEEP, we’re trying to push to the very beginning of reionization when the earliest galaxies really started to form stars, and begin to ionize the intergalactic medium. Whereas Professor Casey’s program is targeting the end of reionization, looking at the descendants of our galaxies and the bubbles they have created around them.”

In terms of how the projects will be carried out, though, “WDEEP is almost the exact opposite,” Finkelstein said. “While COSMOS-Webb is going very wide to look for the brightest and most massive galaxies, WDEEP is going deep. We are going to pick one place in the sky and stare at it for over 100 hours, following in the footsteps of the original Hubble Deep Field,” he said.

He explained that the goal of WDEEP is to push the frontier in terms of the most distant galaxies detected. The team expects to find 50 or more galaxies at a time less than 500 million years after the Big Bang, which is “a completely unexplored epoch” in the universe’s history, he said. And if they’re lucky, they might find a galaxy at just 270 million years after the Big Bang, or 2% of the universe’s present age of 13.8 billion years.

The goal in finding these most-distant galaxies is to help understand the early universe. “There are a wide range of theoretical predictions for what the universe should look like at these times,” Finkelstein said. “Without observations, these predictions are completely unconstrained. Our goal is to try and pin down those models telling us what the earliest galaxies were like.”

Other UT astronomers lead or co-lead JWST first-year projects on a variety of topics. These include faculty members Brendan Bowler, John Chisholm, Harriet Dinerstein, Neal Evans, and Caroline Morley; postdoctoral researchers Micaela Bagley, Will Best, and Justin Spilker; and graduate student Samuel Factor. The projects include studies of planet formation, the failed stars called brown dwarfs, the chemistry of pre-biotic molecules in newly forming stars, early stages of star formation, the dead stars called planetary nebulae, the formation of massive galaxies in the early universe, and more. Together, they will use about 100 hours of telescope time in the telescope’s first year.

From California Institute of Technology (US)

April 19, 2021
COSMOS-Webb selected as JWST’s largest Cycle 1 program

When the James Webb Space Telescope (JWST)—the long-awaited successor to the Hubble Space Telescope—becomes operational in 2022, one of its first orders of business will be mapping the earliest structures of the universe. A team of nearly 50 researchers led by scientists at Rochester Institute of Technology [above] and University of Texas at Austin [above] will attempt to do so through the COSMOS-Webb program, the largest General Observer program selected for JWST’s first year.

Over the course of 208.6 observing hours, the COSMOS-Webb program will conduct an ambitious survey of half a million galaxies with multi-band, high-resolution near infrared imaging and an unprecedented 32,000 galaxies in mid infrared. The scientists involved said that because COSMOS-Webb is a treasury program, they will rapidly release data to the public so it can lead to countless other studies by other researchers.

“The sheer scope of our program is so exciting,” said principal investigator Jeyhan Kartaltepe, an assistant professor at RIT. “The first year of Webb observations will result in a lot of new discoveries that people will want explore more in-depth in future cycles. I think the public legacy of COSMOS-Webb will be that COSMOS will be the field where the community conducts this type of follow-up research.”

Caitlin Casey, an assistant professor and principal investigator at UT Austin, said “COSMOS-Webb has the potential to be ground-breaking in ways we haven’t even dreamt yet. You don’t know what treasures are there to find until you use an incredible telescope like Webb to stare at the sky for a long time.”

The survey will map 0.6 square degrees of the sky—about the area of three full moons—using JWST’s Near Infrared Camera (NIRCam) [above] instrument while simultaneously mapping a smaller area of 0.2 square degrees with the Mid Infrared Instrument (MIRI) [above]. Through this approach, the scientists hope to achieve three main goals.

The first goal focuses on the epoch of reionization [above], which took place from 400,000 to 1 billion years after the big bang. When the first stars and galaxies formed, they provided energy to re-ionize the early universe and it likely happened in little pockets, not all at once. COSMOS-Webb aims to map out the scale of these reionization bubbles.

“At these early epochs, COSMOS-Webb will reveal thousands of galaxies, fainter, more distant and more numerous than those previously discovered with Hubble”, said Anton Koekemoer, a research astronomer in the Webb team at the Space Telescope Science Institute, who helped design the observing strategy for the program.

A second goal is to use the MIRI instrument to look for fully evolved galaxies at high redshifts that seemingly matured soon after the universe formed. Hubble Space Telescope (HST) has found examples of these galaxies, which challenge existing models about how the universe formed, so the hope is to find more examples of these high redshift galaxies and study them in more detail to understand how they could have evolved so rapidly.

The third primary objective makes use of a technique called weak lensing [above]. Because gravity is sensitive to all kinds of matter including that we cannot see, scientists can use the distortions of light around galaxies to estimate of the amount of dark matter. Jason Rhodes, a senior research scientist at NASA’s Jet Propulsion Laboratory, said COSMOS-Webb will provide important insight about how dark matter in galaxies has evolved with the stellar content of galaxies over the age of the universe.

“A key result from the original HST-COSMOS effort over a decade ago was showing that dark matter is the cosmic scaffolding upon which the structures in the universe we see today are formed,” said Rhodes. “COSMOS-Webb will make use of the JWST’s larger mirror to push that dark matter mapping farther in time and to higher resolution maps, allowing us to study how dark matter has influenced the evolution of individual galaxies from the early universe to now.”

COSMOS-Webb is one of just 286 General Scientific Observer programs selected out of more than 1,000 proposals for the telescope’s first year of science, known as Cycle 1. These specific programs will provide the worldwide astronomical community with one of the first extensive opportunities to investigate scientific targets with Webb. NASA is currently targeting Oct. 31, 2021, for JWST’s launch.

The COSMOS-Webb team is made up of 49 astronomers worldwide, including 31 based at US-institutes, 18 at international institutes, and 13 students and postdocs. See the coordinated press release at several institutes, including RIT [above], UT Austin [above], University of California-Santa Cruz (US), University of Durham, University of Bologna [Alma mater studiorum – Università di Bologna](IT), MPG Institute for Astronomy [MPG Institut für Astronomie](DE), Kavli Institute for the Physics and Mathematics of the Universe (JP)-University of Tokyo[(東京大] (JP), and DAWN – University of Copenhagen [Københavns Universitet](DK).

See the full article here .

five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

The NASA/ESA/CSA James Webb Space Telescope will be a large infrared telescope with a 6.5-meter primary mirror. Launch is planned for October 2021.

Webb telescope will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

Webb telescope was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

Webb is an international collaboration between National Aeronautics and Space Administration (US), the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center (US) is managing the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute (US) will operate Webb after launch.

Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

There will be four science instruments on Webb: the Near InfraRed Camera (NIRCam), the Near InfraRed Spectrograph (NIRspec), the Mid-InfraRed Instrument (MIRI), and the Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS). Webb’s instruments will be designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.

Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

Launch is scheduled for later in the decade on an Ariane 5 rocket. The launch will be from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb will be located at the second Lagrange point, about a million miles from the Earth.

ESA50 Logo large

Canadian Space Agency