Skip to main content
  1. Home
  2. Space
  3. News

Astronomers share early images from James Webb’s galaxy survey

Georgina Torbet
By

One of the major aims of the James Webb Space Telescope is to observe some of the earliest galaxies in the universe, and to do that it needs to be able to see extremely distant objects. But looking at a particular very old galaxy in detail is only half of the problem. To truly understand the earliest stages of the universe, astronomers also need to see how these very old galaxies are distributed so they can understand the large-scale structure of the universe.

That’s the aim of the COSMOS-Web program, which is using James Webb to survey a wide area of the sky and look for these rare, ancient galaxies. It aims to study up to 1 million galaxies during over 255 hours of observing time, using both Webb’s near-infrared camera (NIRCam) and its mid-infrared instrument (MIRI) camera. While there is still plenty of observing left to do, the researchers in the COSMOS-Web program recently shared some of their first results.

Images of four example galaxies selected from the first epoch of COSMOS-Web NIRCam observations, highlighting the range of structures that can be seen. In the upper left is a barred spiral galaxy; in the upper right is an example of a gravitational lens, where the mass of the central galaxy is causing the light from a distant galaxy to be stretched into arcs; on the lower left is nearby galaxy displaying shells of material, suggesting it merged with another galaxy in its past; on the lower right is a barred spiral galaxy with several clumps of active star formation.
These images of four example galaxies selected from the first epoch of COSMOS-Web NIRCam observations highlight the range of structures that can be seen. In the upper-left is a barred spiral galaxy; in the upper-right is an example of a gravitational lens, where the mass of the central galaxy is causing the light from a distant galaxy to be stretched into arcs; on the lower-left is sa nearby galaxy displaying shells of material, suggesting it merged with another galaxy in its past; on the lower-right is a barred spiral galaxy with several clumps of active star formation. COSMOS-Web/Kartaltepe, Casey, Franco, Larson, et al./RIT/UT Austin/IAP/CANDIDE

“It’s incredibly exciting to get the first data from the telescope for COSMOS-Web,” said principal investigator Jeyhan Kartaltepe of the Rochester Institute of Technology, in a statement. “Everything worked beautifully, and the data are even better than we expected. We’ve been working really hard to produce science-quality images to use for our analysis, and this is just a drop in the bucket of what’s to come.”

The first images include four galaxies, chosen because they represent the different types of galaxy that the survey will find. There is a barred spiral galaxy, like our Milky Way, and a similar galaxy undergoing vigorous star formation. There is also a galaxy that seems to have recently merged, and one galaxy whose light is bent due to gravitational lensing.

The first epoch of COSMOS-Web NIRCam observations obtained on Jan. 5-6, 2023, including the F115W, F150W, F277W, and F444W filters as a color composite. These data cover six visits or pointings out of a total of 152 visits. The total area covered by NIRCam here is ∼77arcmin^2. The relative position of this mosaic in the survey is shown at upper left. At lower left are several zoomed-in 10′′ × 10′′ cutouts and one 16′′ × 16′′ cutout showing specific galaxies selected from these first data.
The first epoch of COSMOS-Web NIRCam observations obtained on Jan. 5-6, 2023, including the F115W, F150W, F277W, and F444W filters as a color composite.  COSMOS-Web/Kartaltepe, Casey, Franco, Larson, et al./RIT/UT Austin/IAP/CANDIDE

These are just a tiny slice of the galaxies identified by the survey so far. The image above shows the observations taken between January 5 and 6 this year, giving an indication of just how big and detailed the eventual full survey will be. This mosaic was made up of six pointings by the telescope, out of a total of 77 to be made in April and May this year, with a further 69 coming in December 2023 and January 2024.

“This first snapshot of COSMOS-Web contains about 25,000 galaxies — an astonishing number larger than even what sits in the Hubble Ultra Deep Field,” said principal investigator Caitlin Casey of the University of Texas at Austin. “It’s one of the largest JWST images taken so far. And yet it’s just 4% of the data we will get for the full survey. When it is finished, this deep field will be astoundingly large and overwhelmingly beautiful.”

Editors' Recommendations

Topics
Roman Space Telescope will survey the sky 1,000 times faster than Hubble
Georgina Torbet
By Georgina Torbet
March 5, 2023
NASA’s Nancy Grace Roman Space Telescope

Since its launch in 2021, the James Webb Space Telescope has been delighting space fans with its stunning views of space objects near and far. But NASA has another space telescope in the works that will be able to help answer even more of the big questions in astronomy. The Nancy Grace Roman Space Telescope, set to launch in 2027 and colloquially known as Roman, will look at vast areas of space to help cosmologists understand the universe on a large scale.

In astronomy research, it's important to be able to look both in very great detail and on a very wide scale. Telescopes like Hubble and James Webb have exceptional sensitivity, so they can look at extremely distant objects. Roman will be different, aiming to get a broad view of the sky. The image below illustrates the differences between the telescopes, showing what Roman and Hubble can capture in one go and comparing Hubble's detailed, but narrow view to Roman's much wider view.

Read more
James Webb captures an extremely distant triple-lensed supernova
Georgina Torbet
By Georgina Torbet
March 4, 2023
This observation from the NASA/ESA/CSA James Webb Space Telescope features the massive galaxy cluster RX J2129. Due to Gravitational lensing, this observation contains three different images of the same supernova-hosting galaxy, which you can see in closer detail here. Gravitational lensing occurs when a massive celestial body causes a sufficient curvature of spacetime to bend the path of light travelling past or through it, almost like a vast lens. In this case, the lens is the galaxy cluster RX J2129, located around 3.2 billion light-years from Earth in the constellation Aquarius. Gravitational lensing can cause background objects to appear strangely distorted, as can be seen by the concentric arcs of light in the upper right of this image.

Since the start of science operations of the James Webb Space Telescope in July last year, we've been treated to a flood of images showing space targets from nebulae to deep fields. This month, Webb researchers shared a new image captured by the telescope's NIRCam instrument which shows a both gorgeous field of galaxies and an important astronomical phenomenon called gravitational lensing.

The image features a huge galaxy cluster called RX J2129, located 3.2 billion light-years away, which is acting as a magnifying glass and bending light coming from more distant galaxies behind it. That's what is causing the stretched-out shape of some of the galaxies toward the top right of the image.

Read more
Astronaut captures ‘unreal’ aurora image from space station
Trevor Mogg
By Trevor Mogg
March 1, 2023
An aurora as viewed from the ISS.

A geomagnetic storm caused by a series of recent explosive events on the sun has brought spectacular auroras to parts of Earth in recent days.

Astronauts on the International Space Station (ISS) 250 miles above our planet have also been enjoying the amazing light show, with ISS inhabitant Josh Cassada sharing a stunning image that he captured just recently.

Read more