Oort Fellow at Leiden Observatory
I'm an astrochemist specialised in the chemistry around evolved stars. In particular, I develop chemical kinetics models of the outflows of Asymptotic Giant Branch stars and use these to interpret observations of these complex environments.
Spherically symmetric AGB outflows appear to be the exception rather than the rule. Large-scale structures, such as spirals and disks, and small-scale clumpiness is ubiquitously observed. For a chemical model of a circumstellar environment (CSE) to be able to interpret observations, these complexities have to be included.
The Rate22 CSE model is available here, part of the latest release of the UMIST Database for Astrochemistry. The model includes the effects of a close-by stellar companion and a clumpy outflow.
My other models also include a comprehensive dust-gas chemistry, including the formation of ices and refractory organic material on the dust's surface. The disk around L2 Puppis has its own chemical model. While these aren't publicly available yet, I'm happy to chat!
These 1D models can only go so far. Hydrodynamical models are necessary to explain the wide variety of complexities. Coupling chemistry to these models is computationally challenging, but emulating can help! Silke Maes developed the first chemical emulator, MACE, available here. More coming up...
Chemical models are essential to help interpret the complex dynamics within AGB outflows. For example, chemistry can be used to infer the presence of a stellar companion (like around IRC+10216) and even to infer the orbital parameters (like around W Aql).
Dust-gas chemistry can shed a light on the dust grain-size distribution and can help explain depletion of refractory molecules. There are plenty of chemical tracers for a variety of physics and chemistry, have a look here or feel free to send me an email if you're designing a new observing campaign.
ALMA observations of the disk around L2 Pup are on their way!
You can find all of my publications on NASA-ADS
Employment
2023 - now: Oort Fellow at Leiden Observatory, the Netherlands
2021 - 2023: Marie Skłodowska-Curie Individual Fellow at the University of Leeds, UK
2018 - 2021: Postdoctoral Fellow of the Research Foundation Flanders (FWO), KU Leuven, Belgium
Education
2014 - 2018: PhD in Astronomy and Astrophysics, KU Leuven, Belgium
Invited talks
Jul 2024: Invited speaker at Scientific Event “Chemical complexity of the molecular universe” at COSPAR 2024, Busan, South Korea
Jul 2023: Keynote speaker at the 2023 Kavli-IAU Astrochemistry Symposium: Astrochemistry VIII – From the First Galaxies to the Formation of Habitable worlds, Traverse City, USA
Oct 2022: Invited speaker at the Niels Bohr Gold Medal Symposium in Astrochemistry in Copenhagen, Denmark
Jul 2022: Invited speaker at “Taming the Uncertainty Monster: Lessons from Astrochemistry?”, an interdisciplinary workshop reuniting astrochemists, astrophysicists and philosophers, Rennes, France
Jul 2021: Invited keynote speaker at Astrochemical Frontiers - Quarantine Edition 2
May 202: Invited plenary talk at GAPS 2021 - unsolved problems in red Giants And suPergiantS
I enjoy talking about my research and astrochemistry to a wide range of audiences. Some online examples include Pint of Science and a Question of the Week for Technopolis (Dutch).
My passion for public speaking was recognised with the 2023 Caroline Herschel Prize Lectureship, awarded to promising women in astronomy. The lectures at the University of Bath and at the Royal Astronomical Society are both online.
You can email me at mvdsande [at] strw.leidenuniv.nl