/ 15 July 2022

What does that gorgeous, mysterious Webb Telescope image of cosmic cliffs reveal?

Jameswebb
Dazzling: The James Webb Space Telescope’s first images include the Cosmic Cliffs, a gaseous cavity 7 600 light years away. Photo: Nasa

NASA this week released the first set of science-quality images from the powerful James Webb Space Telescope, which is expected to “find the first galaxies that formed in the early universe and peer through dusty clouds to see stars forming planetary systems”. 

The telescope is situated 1.5-million kilometres away from Earth, at the second Lagrange (L2) point, with its predecessor, Hubble, at a much closer orbit. 

Using the Webb, astronomers combined the capabilities of the telescope’s two cameras to create a never-before-seen view of a star-forming region in the Carina Nebula. 

Captured in infrared light by the near-infrared camera (NIRCam) and mid-infrared instrument (MIRI), this combined image reveals previously invisible areas of star birth. 

What looks much like craggy mountains on a moonlit evening is actually the edge of a nearby, young, star-forming region known as NGC 3324. Called the Cosmic Cliffs, this rim of a gigantic, gaseous cavity is roughly 7 600 light years away. 

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 centre of the bubble, above the area shown in this image. 

The high-energy radiation from these stars is sculpting the nebula’s wall by slowly eroding it away. NIRCam — with its crisp resolution and unparalleled sensitivity — unveils hundreds of previously hidden stars, and even numerous background galaxies. 

In the MIRI’s view, young stars and their dusty, planet-forming disks shine brightly in the mid-infrared, appearing pink and red. The MIRI shows structures that are embedded in the dust and uncovers the stellar sources of massive jets and outflows. 

With the MIRI, the hydrocarbons and other chemical compounds on the surface of the ridges glow, giving the appearance of jagged rocks. 

The faint “steam” that appears to rise from the celestial “mountains” is actually hot, ionised gas and hot dust streaming away from the nebula caused by ultraviolet radiation. 

Peaks and pillars rise above the glowing wall of gas, resisting the blistering ultraviolet radiation from the young stars. 

Bubbles and cavities are being blown by the intense radiation and stellar winds of newborn stars. 

Protostellar jets and outflows, which appear in gold, shoot from dust-enshrouded, nascent stars. 

The MIRI uncovers the young, stellar sources producing these features. For example, a feature at left that looks like a comet with NIRCam is revealed with the MIRI to be one cone of an outflow from a dust-enshrouded newborn star.

A “blow-out” erupts at the top-centre of the ridge, spewing material into the interstellar medium. The MIRI sees through the dust to unveil the star responsible for this phenomenon. 

An unusual “arch,” looking like a bent-over cylinder, appears in all wavelengths shown here. This period of very early star formation is difficult to capture because, for an individual star, it lasts only about 50 000 to 100 000 years — but Webb’s extreme sensitivity and exquisite spatial resolution have chronicled this rare event. 

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. 

NIRCam was built by a team at the University of Arizona and Lockheed Martin’s Advanced Technology Centre. 

The MIRI was contributed by the European Space Agency and Nasa, with the instrument designed and built by a consortium of nationally funded European institutes (the MIRI European Consortium) in partnership with the Jet Propulsion Laboratory and the University of Arizona. — Space Telescope Science Institute (STScI)


For a full array of Webb’s first images and spectra, including downloadable files, visit: https://webbtelescope.org/news/first-images.