Cosmic dust grains are fundamental to the formation and evolution of planets, stars and galaxies across the whole history of the Universe. Our Wallenberg funded project combines unique interdisciplinary research within astronomy from galactic evolution, black holes, and stellar evolution with novel theoretical models in physical chemistry in a focused effort to address the fundamental question of the origin and fate of dust in the Universe – an unsolved puzzle within astrophysics. Dust grains play a key role in essentially all astrophysical contexts. It is found on all scales throughout the Universe and is formed in varying and often extreme environments, from the earliest Universe until today. These different stellar and galactic environments directly affect the properties of the dust grains. Core and affiliated members of our team at Chalmers University of Technology are at the forefront of research into dust around evolved stars, black hole evolution and stellar growth in nearby galaxies, and dust at cosmological distances. The team members at the physical chemistry group of Gothenburg University are experts at studying the survival and growth of stellar dust species. Combining new theoretical models of dust processing with new observational research, our team aims to make significant contributions to the description of the formation of dust, its evolution, and effect on astrophysical environments throughout cosmic time.

Below, we highlight a few of the research areas that the project will focus on. The team will specifically establish areas where expertise from one of the observational or theoretical topics provides unique added-value for one of the other research topics, both within the project team as well as with an extensive local and international collaborative network.

Example Research topics

Microscopic aspects of dust formation and destruction

Dust in the universe is formed and destroyed under diverse physical conditions. We will investigate details of these processes subject to radiation and shocks, i.e. bombardment by photons or by small particles like molecules, atoms, ions or electrons. This will be done at an atomic level using classical trajectory calculations and quantum mechanically based approaches. We will develop the necessary models to do this.

Dust from Evolved Stars and (Super)novae

The seeds of astrophysical dust are produced around stars that inject the dust into the interstellar medium through winds (ISM) or in explosive events. Using state-of-the-art observation techniques, including polarimetery, we will describe and model the changes in grain size, structure and composition throughout stellar winds. We then will investigate theoretically how this dust is processed with it traverses different shocks on its way into the ISM. We will include studies of AGB stars, (post-)common envelope sources, novae and supernovae.

Scattered light produced by dust around the AGB star R Crt (Khouri et al. 2020)
Dust in galactic nuclei

We will study the dust properties, including its growth and destruction, in obscured galactic nuclei and their in- and outflows. Our aim is to chart the interplay between dust and the evolution of the galaxy nuclei along with star formation and black hole accretion. We will compare with high-resolution observations of the dynamics and physical conditions of the gas. We aim for a comprehensive account of the dust in the high-density environments in galaxy nuclei – including effects of black hole accretion and star formation. The evolution of the galaxy nuclei will be modelled including the role of dust, the feedback of dust to the ISM, and the effect on the dust properties.

HST V-band observations of the inner region of NGC 1377 (Gallagher, Aalto et al., in prep.)
Dust at high redshift

The discovery of several dust-rich galaxies less than a billion years after the Big Bang demonstrates the rapid production of both elements heavier than He, formation of dust seed particles, and the rapid growth of the dust grains.  However, a growing number of dust-poor galaxies are being discovered, showing a very wide range of conditions in the early universe.  As dust is an essential ingredient for the formation of stars, even in early galaxies, it is imperative to understand their properties, and how these potentially differ from local galaxies.  The time scale for grain growth has been shorter than in local galaxies, but also the abundance of elements, the potential stronger UV-radiation field, and the higher temperature of the cosmic microwave background, likely all play an important role in the dust formation and destruction.  We will focus on how this affects our interpretation of observational results, and on modelling of how these different environment conditions might affect the physical properties of the grains. 

The dust-rich, gravitationally lensed z=7 galaxy A1689-zD1 (Watson, Christensen, Knudsen et al., 2015, Nature)
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