DiRAC user Sahl Rowther, now a postdoc in the Department of Physics & Astronomy at Leicester University, has been selected to present a poster describing his research at the prestigious STEM for Britain event held at the Houses of Parliament on Tuesday 17th March 2026.
Sahl’s research models the evolution of protoplanetary discs; self-gravitating discs forming around young stars. His simulations investigate how their evolution is altered by physical processes such as planet-disc interactions and warps (when coplanar discs are slightly mis-aligned). In the last decade, our understanding of protoplanetary discs has been revolutionised by the discovery of diverse sub-structures visible across a wide range of spatial & temporal scales. Many discs exhibit a pattern of bright rings and dark gaps, usually interpreted as a signature of a massive planet carving open a path around its orbit. However, the young ages of the protoplanetary discs then raise a major challenge: how do planets form quickly enough to generate the sub-structures we observe?
Figure 1: The final state of a 0.25 Solar mass disc modelled with live radiative transfer. Despite gravitational instabilities being weaker, the disc has fragmented, forming clumps.
Sahl and his collaborators have used 3D Smooth Particle Hydrodynamics simulations incorporating both gas and dust components to show how the conditions in young, massive discs do provide efficient breeding grounds for rapid planet formation. A characteristic feature of young discs is their large spiral arms. These simulations show that dust can become trapped in the spiral arms, clumping together to create the building blocks of planets, and hence providing a pathway to explaining the ring & gap structures observed in the youngest discs.
In Sahl’s own words “I am delighted to be presenting my work on rapid planet formation in gravitationally unstable discs at STEM for Britain. It’s a rare and invaluable opportunity to share directly with members of parliament how research into planet formation advances our understanding of planetary systems and drives innovation in modelling and high performance computation. Engaging with policy-makers helps ensure that long-term investment into astrophysics continues to be supported.”
Details about simulations:
Most of the simulations in Sahl’s work involve 3d hydrodynamics coupled with Monte Carlo radiative transfer. These are incredibly computationally expensive and are only possible with the availability of high performance computing resources. Among other facilities, Sahl’s work uses DiRAC’s Data Intensive (DiAL) service at Leicester.
Related Papers
Short-lived gravitational instability in isolated irradiated discs
Leading and trailing spiral arms in a nearly broken protoplanetary disc
Figure 2: The evolution of large dust grains (St ~ 4) in a gravitationally unstable disc. Each panel shows the same simulation setup. The only difference between the four panels is the physics.
