The Life & Times of Polycyclic Aromatic Hydrocarbons

Speaker: Karin Sandstrom (UC San Diego) In Person and zoom 

Zoom Recording Passcode: i.7a8^53

Despite being less than ~5% of the interstellar dust mass, small carbonaceous grains called polycyclic aromatic hydrocarbons (PAHs) play critical roles in the physics of the interstellar medium (ISM). They dominate the photoelectric heating of neutral gas, catalyze molecular hydrogen formation, make important contributions to UV extinction, and re-radiate up to 20% of the starlight absorbed by dust in the mid-IR. And yet, the origins and fates of these small grains remain mysterious! With its incredible angular resolution, sensitivity, and spectroscopic capabilities, JWST is set to revolutionize our knowledge about the life cycle of PAHs.  I will present new insights, gained from the first 3 years of JWST operations, into the formation, evolution, and destruction of PAHs. I will also discuss some of the key future observations with JWST, SPHEREx, and beyond that will help unravel the story of PAHs and their role in our cosmic origins.