November 04, 2022
The James Webb Space Telescope (JWST) found polycyclic aromatic hydrocarbons (PAHs) in three active galaxies' centers, where scientists thought they couldn't survive.
The radiation near these galaxies' supermassive black holes may have changed the PAHs' characteristics, which might confound a crucial tool astronomers use to measure star formation and impair their function as biological building blocks.
Oxford University astrophysicist Ismael García-Brunette headed a team of astronomers who evaluated JWST's Mid-Infrared Instrument data of three active galaxies (MIRI).
PAHs are carbon-ring compounds. From faraway galaxies to solar system comets, these chemicals are ubiquitous.
Their abundance makes them useful building blocks for life and star-formation tracers.
García-Bernete wanted to know if PAH emission in an active galaxy's dense, ultraviolet-rich center was the same as in its spiral arms' calmer star-forming regions.
Stars can emerge in the centers of active galaxies, but gas falling onto a supermassive black hole releases ultraviolet radiation that makes PAHs glow.
The strong radiation around an active galaxy's supermassive black hole was projected to destroy all PAH molecules.
The emission was from larger, electrically neutral PAH molecules, confirming that radiation had eliminated smaller, charged PAHs.