Determine the effect of stellar irradiation on spiral morphology at higher resolution

Determine how stellar irradiation influences the morphology of gravitationally unstable spiral structures in protostellar discs by conducting higher-resolution simulations of discs in which stellar irradiation significantly affects the temperature.

Background

The paper finds that discs subject to stronger stellar irradiation tend to remain axisymmetric or fragment at higher disc-to-star mass ratios, while lower-luminosity stars permit spiral structures to form. In the irradiated cases, the spiral structures are typically fainter and involve higher-order modes rather than the prominent low-m grand-design spirals often associated with gravitational instability.

The authors do not resolve the physical origin or robustness of this apparent connection between stellar irradiation and spiral morphology. They explicitly identify higher-resolution simulations as necessary to elucidate the effect, making this an unresolved problem rather than a general suggestion for future research.