Dust2020 — The Rise of Metals and Dust in Galaxies through Cosmic Time

Before the birth of the first generation of stars (population III), the universe contained essentially only hydrogen and helium atoms. But after these first stars ignited, they synthesized in their cores nuclei of atoms heavier and heavier (the rise of metals). Some of these atoms have formed grains of dust, which is now everywhere in the interstellar medium. Dust absorbs and diffuses ultraviolet radiation and optical light, which heats the dust particles that ultimately produce radiation that is re-emitted in the infrared. This process modifies our vision of galaxies and of the universe and has dominated the universe for several billion years (the rise of dust). In addition to the effects of reddening and obscuration, dust grains also play a crucial role in star formation and in the physics and chemistry of the interstellar medium, such as heating and cooling processes, gas dynamics, charge transfer and the formation of H2 molecules. It is therefore important to progress in understanding the history of the formation of heavy elements in the universe as well as the different phases of the duty cycle of dust and the variation of this cycle according to the environment and the cosmic times.