NASA’s James Webb Space Telescope (JWST) is celebrating four years of unexpectedly strong performance by providing a deep new view into one of the universe’s most familiar galaxies: Centaurus A.
Typically, Centaurus A’s thick dust obscures astronomers’ attempts to peer into it, yet the JWST’s near- and mid-infrared sensitivity allows scientists to see more of the galaxy than ever before.
In new images released by NASA to celebrate JWST’s four years of impressive discoveries, the most powerful telescope ever constructed reveals the dense collection of stars that make up the ever-changing Centaurus A galaxy.
Inside Centaurus A
Due to two crucial factors, Centaurus A is an extremely interesting galaxy for astronomers. It is highly active, offering an important opportunity to monitor galaxy and black hole growth while being relatively close by, at just 11 million light-years away—a highly unusual combination.
The history of imaging Centaurus A is marked by questions, which JWST has now begun to answer. Webb’s predecessor, Hubble, could only view visible light in its examinations, leaving the galaxy’s central regions obscured by dust. Additionally, the Spitzer Space Telescope lacked sufficient resolution to resolve individual stars in infrared, although the data it collected provided new discoveries of massive dust structures.
Powerful events are on display in Centaurus A, the aftermath of a collision with another galaxy and a supermassive black hole’s active feeding. As the black hole releases powerful jets and gushes energy, it shapes the surrounding galaxy, which still retains an unusual shape left by its two-billion-year-old merger.
“No single telescope tells the whole story,” said Shawn Domagal-Goldman, division director, Astrophysics, NASA Headquarters in Washington. “Discoveries build over time, and new observatories expand on the foundations laid by earlier missions. Webb represents the most powerful step forward yet, opening a window into wavelengths and details never before accessible. This allows astronomers to examine structures and processes that other telescopes could not see.”
JWST Reveals Amazing Structures
Thanks to JWST’s mid-infrared capabilities, astronomers captured detailed images of Centaurus A’s dust structures and were surprised and confused by the glowing shapes revealed. One unusual feature is a band cutting across the galactic center, shaped like a warped parallelogram, with wispy tendrils stretching out of it.
Another feature, shaped like the letter “S,” also confounds astronomers, leaving many questions about the influence of both the central black hole and the galactic merger on its shape and evolution.
A large portion of the red glowing dots in the image above represent dusty areas, either dust-rich stars or stellar nurseries, both important sources of dust for star formation, and therefore, the continuance of the galaxy.
Single Stars and JWST
The JWST’s incredible resolution is allowing astronomers to study the galaxy star by star for the first time. Combining images from the MIRI (Mid-Infrared Instrument) and the NIRCam (Near-Infrared Camera) revealed tightly packed individual stars.
This view of individual stars is essential for what some astronomers call “galactic archaeology,” by providing important clues that help scientists reconstruct the galaxy’s formation and evolution. This galactic timeline is made up of many important pieces revealed by individual stars, such as when the oldest stars formed, when star formation slowed, when the merger reignited a powerful burst of star formation, and how that collision stirred the galaxy’s gases, further accelerating star formation.
Capturing these details requires spectroscopy, a technique where light is broken down to reveal detailed information about distant stars. Also using this technique, researchers can gain important information about the central black hole, identifying that it can both compress gas to accelerate star formation and push gas away to limit it.
On its fourth anniversary, the unprecedented details now revealed about one of our most interesting galactic neighbors continue to underscore the JWST’s incredible promise as NASA’s premier space observatory.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.