NASA’s Webb Telescope Captures Deepest Infrared Image of Universe To Date
By Space Coast Daily // July 12, 2022
image shows galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago
(NASA) – NASA’s James Webb Space Telescope has delivered the deepest and sharpest infrared image of the distant universe so far.
Webb’s First Deep Field is galaxy cluster SMACS 0723, and it is teeming with thousands of galaxies – including the faintest objects ever observed in the infrared.
Webb’s image is approximately the size of a grain of sand held at arm’s length, a tiny sliver of the vast universe. The combined mass of this galaxy cluster acts as a gravitational lens, magnifying more distant galaxies, including some seen when the universe was less than a billion years old.
This deep field, taken by Webb’s Near-Infrared Camera (NIRCam), is a composite made from images at different wavelengths, totaling 12.5 hours – achieving depths at infrared wavelengths beyond the Hubble Space Telescope’s deepest fields, which took weeks. And this is only the beginning.
Researchers will continue to use Webb to take longer exposures, revealing more of our vast universe.
This image shows the galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago, with many more galaxies in front of and behind the cluster. Much more about this cluster will be revealed as researchers begin digging into Webb’s data.
This field was also imaged by Webb’s Mid-Infrared Instrument (MIRI), which observes mid-infrared light.
Webb’s NIRCam has brought distant galaxies into sharp focus – they have tiny, faint structures that have never been seen before, including star clusters and diffuse features.
Light from these galaxies took billions of years to reach us. We are looking back in time to within a billion years after the big bang when viewing the youngest galaxies in this field.
The light was stretched by the expansion of the universe to infrared wavelengths that Webb was designed to observe. Researchers will soon begin to learn more about the galaxies’ masses, ages, histories, and compositions.
Other features include the prominent arcs in this field. The powerful gravitational field of a galaxy cluster can bend the light rays from more distant galaxies behind it, just as a magnifying glass bends and warps images. Stars are also captured with prominent diffraction spikes, as they appear brighter at shorter wavelengths.
Webb’s MIRI image offers a kaleidoscope of colors and highlights where the dust is – a major ingredient for star formation, and ultimately life itself. Blue galaxies contain stars, but very little dust. The red objects in this field are enshrouded in thick layers of dust. Green galaxies are populated with hydrocarbons and other chemical compounds. Researchers will be able to use data like these to understand how galaxies form, grow, and merge with each other, and in some cases why they stop forming stars altogether.
In addition to taking images, two of Webb’s instruments also obtained spectra – data that reveal objects’ physical and chemical properties that will help researchers identify many more details about distant galaxies in this field. Webb’s Near Infrared Spectrograph (NIRSpec) microshutter array observed 48 individual galaxies at the same time – a new technology used for the first time in space – returning a full suite of details about each.
The data revealed light from one galaxy that traveled for 13.1 billion years before Webb’s mirrors captured it. NIRSpec data also demonstrate how detailed galaxy spectra will be with Webb observations.
Finally, Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) used Wide-Field Slitless Spectroscopy to capture spectra of all the objects in the entire field of view at once. Among the results, it proves that one of the galaxies has a mirror image.
SMACS 0723 can be viewed near the constellation Volans in the southern sky.
- NASA’s James Webb Space Telescope reveals emerging stellar nurseries and individual stars in the Carina Nebula that were previously obscured
- Images of “Cosmic Cliffs” showcase Webb’s cameras’ capabilities to peer through cosmic dust, shedding new light on how stars form
- Objects in the earliest, rapid phases of star formation are difficult to capture, but Webb’s extreme sensitivity, spatial resolution, and imaging capability can chronicle these elusive events
This landscape of “mountains” and “valleys” speckled with glittering stars is actually the edge of a nearby, young, star-forming region called NGC 3324 in the Carina Nebula. Captured in infrared light by NASA’s new James Webb Space Telescope, this image reveals for the first time previously invisible areas of star birth.
Called the Cosmic Cliffs, Webb’s seemingly three-dimensional picture looks like craggy mountains on a moonlit evening. In reality, it is the edge of the giant, gaseous cavity within NGC 3324, and the tallest “peaks” in this image are about 7 light-years high. The cavernous area has been carved from the nebula by the intense ultraviolet radiation and stellar winds from extremely massive, hot, young stars located in the center of the bubble, above the area shown in this image.
The blistering, ultraviolet radiation from the young stars is sculpting the nebula’s wall by slowly eroding it away. Dramatic pillars tower above the glowing wall of gas, resisting this radiation. The “steam” that appears to rise from the celestial “mountains” is actually hot, ionized gas and hot dust streaming away from the nebula due to the relentless radiation.
Webb reveals emerging stellar nurseries and individual stars that are completely hidden in visible-light pictures. Because of Webb’s sensitivity to infrared light, it can peer through cosmic dust to see these objects. Protostellar jets, which emerge clearly in this image, shoot out from some of these young stars. The youngest sources appear as red dots in the dark, dusty region of the cloud. Objects in the earliest, rapid phases of star formation are difficult to capture, but Webb’s extreme sensitivity, spatial resolution, and imaging capability can chronicle these elusive events.
These observations of NGC 3324 will shed light on the process of star formation. Star birth propagates over time, triggered by the expansion of the eroding cavity. As the bright, ionized rim moves into the nebula, it slowly pushes into the gas and dust. If the rim encounters any unstable material, the increased pressure will trigger the material to collapse and form new stars.
Conversely, this type of disturbance may also prevent star formation as the star-making material is eroded away. This is a very delicate balance between sparking star formation and stopping it. Webb will address some of the great, open questions of modern astrophysics: What determines the number of stars that form in a certain region? Why do stars form with a certain mass?
Webb will also reveal the impact of star formation on the evolution of gigantic clouds of gas and dust. While the effect of massive stars – with their violent winds and high energy – is often apparent, less is known about the influence of the more numerous low-mass stars. As they form, these smaller stars create narrow, opposing jets seen here, which can inject a lot of momentum and energy into the clouds. This reduces the fraction of nebular material that seeds new stars.
Up to this point, scientists have had very little data about the influence of the multitude of young and more energetic low-mass stars. With Webb, they will be able to obtain a full census of their number and impact throughout the nebula.
Located roughly 7,600 light-years away, NGC 3324 was imaged by Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI).
NIRCam – with its crisp resolution and unparalleled sensitivity – unveils hundreds of previously hidden stars, and even numerous background galaxies.
In MIRI’s view, young stars and their dusty, planet-forming disks shine brightly in the mid-infrared, appearing pink and red. MIRI reveals structures that are embedded in the dust and uncovers the stellar sources of massive jets and outflows. With MIRI, the hot dust, hydrocarbons, and other chemical compounds on the surface of the ridges glow, giving the appearance of jagged rocks.
NGC 3324 was first catalogued by James Dunlop in 1826. Visible from the Southern Hemisphere, it is located at the northwest corner of the Carina Nebula (NGC 3372), which resides in the constellation Carina. The Carina Nebula is home to the Keyhole Nebula and the active, unstable supergiant star called Eta Carinae.