Carbon cycle ratios in evolved molecular clouds: selecting the best H2 tracer

• Applicant: Dr. Thomas Bisbas, Ph.D.
• Subject Area: Astrophysics and Astronomy
• Term: from 2019 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 424563772

The goal of the proposed research is to study the full carbon cycle in relation to the important atomic-to-molecular (HI-to-H2) transition in different environments with the aim to understand the interstellar medium (ISM) properties of the low- and high- redshift Universe.By relating the carbon cycle to the HI-to-H2 transition, I will estimate the emission lines of the ionized (CII), atomic (CI) and molecular (CO) carbon, which will result in building appropriate conversion factors to estimate the molecular gas mass more robustly than has ever been achieved.The study will combine state-of-the-art astrochemical and radiative transfer codes I have developed, detailed three-dimensional hydrodynamical simulations from the SILCC project that the host institution leads and multiwavelength observations of the supernova remnant IC443 which will be used as a laboratory to study the efficiency of CO destruction by cosmic-rays and X-rays. In particular, I will examine how the carbon cycle observations of molecular clouds change when interacting with nearby SNe.In addition, I will develop a novel and fast statistical approach to determine the average ISM properties from given column density (extinction) probability density functions which will be extensively benchmarked with SILCC simulations.By the end of the Fellowship, I will release an online platform of a user-friendly and easy-access interactive environment which will offer the ability to estimate the average brightness temperatures of the CO ladder, [CI] and [CII] lines from any given distribution of column densities, when simultaneously considering the detailed photodissociation region chemistry.The project will impact the community of Observational Astrophysics at large and will provide important results and tools for forthcoming telescopes such as CCAT-prime and the Cherenkov Telescope Array.

• DFG Programme: Research Grants