Photodissociation and X-ray Dominated Regions

Abstract:

The radiation from stars and active galactic nuclei creates photodissociation regions (PDRs) and X-ray dominated regions (XDRs), where the chemistry or heating are dominated by far-ultraviolet (FUV) radiation or X-ray radiation, respectively. PDRs include a wide range of environments from the diffuse interstellar medium to dense star-forming regions. XDRs are found in the center of galaxies hosting AGN, in protostellar disks, and in the vicinity of X-ray binaries. In this talk I will present the recent ARAA review on PDR and XDR physics that I wrote with M. Wolfire and M. Chevance. This represents an overview on the state-of-the-art in the field, after 25 years from the last review on the topic. I will describe the dominant thermal, chemical, and radiation transfer processes in PDRs and XDRs, as well as a brief description of models and their use to analyze observations. I will then present recent results from the Milky Way, nearby extragalactic, and high-redshift observations.

Il seminario si terrà in presenza. Chi fosse interessato a partecipare deve scrive a classi@sns.it entro le 10:00 di Mercoledì 30 marzo 2022.