Invited Talk - Plenary

Tuesday, 13 September 2022, 12:00   (Keksdose / virtual plenum)

Small Molecules, Big Impact: Investigating hydrides in the interstellar medium

Arshia Jacob
Johns Hopkins University, Baltimore, USA

The nature and distribution of atomic and molecular gas in the interstellar medium (ISM) is of great interest to astrophysicists because it is this gas that provides the raw material for the formation of new stars. In this talk, I will discuss work that was carried out as a part of my dissertation investigating hydride molecules in the ISM and their use as diagnostics of its different phases. Particular emphasis is given to the central CH radical, a probe of diffuse and translucent molecular clouds, including those not traced by the otherwise common CO. I will detail our searches for the rare isotopologues of CH and address questions regarding the origin of another molecule, CH2, which despite being chemically associated with the ubiquitous CH, has largely remained elusive. And lastly, I will discuss the transition from the diffuse atomic to the diffuse and translucent molecular phases of the ISM by extending our view of the chemistry of argonium, ArH+, a tracer of almost purely atomic gas.