rich mix of organic molecules deep inside a nearby galaxy, offering a new glimpse into how the basic ingredients of chemistry may form in some of the universe’s most extreme environments.
The discovery comes from observations of a galaxy called IRAS 07251–0248, classified as an ultra-luminous infrared galaxy.
These galaxies shine intensely in infrared light because their central regions are wrapped in thick clouds of gas and dust.
In this case, the dust is so dense that it blocks almost all visible light from the galaxy’s core, hiding what is happening near its central supermassive black hole.
JWST is uniquely suited to this challenge. Its instruments can observe infrared wavelengths that pass through dust, allowing scientists to see into places that were previously inaccessible.
By analyzing infrared light across a wide range of wavelengths, researchers were able to identify the chemical fingerprints of many molecules and determine how warm they are and how abundant they might be.
What they found was surprising. The galaxy’s hidden nucleus contains large amounts of small organic molecules such as methane, benzene, acetylene, and longer chain hydrocarbons.
Most strikingly, the team detected the methyl radical, a highly reactive molecule, outside the Milky Way for the first time.
Alongside these gas-phase molecules, the observations also revealed solid materials, including water ice and carbon-rich dust grains.
The sheer amount and variety of these molecules went beyond what existing theories predicted. This suggests that there is an ongoing source of fresh carbon feeding this chemical richness.
Scientists believe the answer lies in cosmic rays—high-energy particles that are especially common in energetic galactic centers.
These cosmic rays can smash into large carbon-based molecules and dust grains, breaking them apart and releasing smaller organic molecules into the surrounding gas.
Although these simple molecules are not part of living cells, they are important stepping stones in chemistry.
On Earth and elsewhere, similar small compounds are thought to take part in reactions that eventually lead to more complex molecules, such as amino acids and nucleotides, which are essential for life.
The study also found that galaxies with stronger cosmic-ray activity tend to show higher amounts of these hydrocarbons, reinforcing the idea that cosmic rays are driving this chemistry.
This means that deeply buried galactic nuclei like this one may act as natural factories for organic molecules, shaping the chemical evolution of galaxies over time.
By lifting the veil on one of the universe’s most obscured environments, JWST has shown how powerful it can be in exploring hidden regions of space.
These findings open a new window onto the cosmic processes that create and recycle the building blocks of organic chemistry, even in places dominated by extreme energy and dust.
Source: University of Oxford.
