The lifecycle of grains in the evolving, multiphase ISM

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Dust grains are tiny solid particles that are present in the interstellar space of any galaxy. These grains absorb the radiation from stars and completely change the appearance of galaxies. In order to remove the dust veil from galaxies and correctly infer their parameters from observations, one needs to know dust properties in different environments, which are not well understood. My research aims to build a consistent picture of the lifecycle of interstellar grains: how they are formed, processed and destroyed in the interstellar gas.Grains are born in cooling gas around old stars and supernovae. The role of stars in the production of dust grains is much better understood now due to recent advances in theoretical models. The following journey of grains in the interstellar space is more complex and less studied theoretically. The major challenge for such studies is that the evolution of interstellar dust and gas are interrelated. My project aims to overcome this challenge by modelling galactic gas and dust evolution simultaneously. We will perform three-dimensional hydrodynamic simulations of galactic evolution that follow all stages of the lifecycle of dust. These simulations will tell us how grain properties vary across the galaxy.Although dust grains constitute only 1% of the gas mass in our galaxy, they are very important for heating and cooling of the gas and for the formation of hydrogen molecules, the most important molecule for formation of stars and planets. Most hydrodynamic simulations of galaxies assume that grains remain the same. Knowing actual properties of grains will enable more realistic modeling of galactic evolution, star formation and help to more accurately interpret the observations of galaxies.