Abstract

Poster - Splinter LowMet

Friday, 13 September 2024, 17:45   (S23)

The impact of variable far-UV radiation field and cosmic-ray ionisation rate on the formation of molecular clouds in low-metallicity environments

Sanjit Pal, Vittoria Brugaletta, Tim-Eric Rathjen, Stefanie Walch-Gassner
Universität zu Köln

This work investigates the formation of molecular clouds in the multi-phase interstellar medium (ISM) at a metallicity of 0.5 Z_sun using magneto-hydrodynamic SILCC-Zoom simulations, with a resolution up to 0.12 pc. Since cooling processes in the low-metallicity ISM are inefficient, a more accurate modeling of heating mechanisms is needed to understand how molecular cloud formation can vary in such environments, compared to the gas in solar-neighbourhood conditions. We present two simulations employing a different modeling of the two main heating mechanisms, the photoelectric heating and the heating due to low-energy cosmic rays. For one run, we use a static interstellar radiation field (ISRF) value and a constant cosmic ray ionisation rate (CRIR). The second run employs two novel methods to describe photoelectric and cosmic-ray heating, using a variable ISRF as implemented in Rathjen et al. (in prep.), and a variable CRIR as presented in Brugaletta et al. (in prep.) These simulations are then compared with previous SILCC-Zoom simulations of solar neighbourhood conditions (Seifried et al. 2017, 2020) to provide a better understanding of the role of metallicity and their corresponding heating and cooling mechanisms.