Unveiling dust properties across galactic environments with dust evolution models
Models of interstellar dust evolution of increasing complexity can be used to study dust content of galaxies on multiple spacial scales. One-zone evolution models constrained by observations reveal how global dust content evolved with time and which dust sources dominated in different epochs of galactic evolution. I will highlight our results from comparisons of such models with extragalactic observations performed by the Spitzer and Herschel Space Telescopes. Small scale variations of dust properties in our own galaxy contain the information about cycling and processing of grains in different phases of the ISM. I will present a new three-dimensional model of dust evolution in a multi-phase, inhomogeneous ISM based on hydrodynamical simulations of giant molecular clouds in a Milky Way-like spiral galaxy. The resolution of the simulations allows us to interpret these observations and shed light on dust growth by accretion in the ISM, the key mechanism of dust formation in the local Universe. I will discuss the variations of the dust-to-gas ratio in the Galactic disk resulting from the cycles of dust destruction and re-formation in the multi-phase ISM.