Presentation #102.71 in the session Poster Session.
A gap in a protoplanetary disc is a low-density region of dust and gas that can be the result of a planet forming. Though the dust only accounts for of the disc by mass, it accounts for the majority of the radiative transfer. The thermal structure of the disc largely controls the paths of icelines and, therefore, the planet’s composition; however, the effect of variations in dust surface density on disc temperature has been poorly understood until now. In this study, we use the radiative transfer code MCMax to model the 2D dust thermal structure with individual gaps corresponding to planets 0.1–5 Jupiter masses and orbital radii of 3, 5, and 10 AU. The low density of the dust in the gap region reduces the optical depth, allowing radiation to penetrate deeper into the disc and warm the midplane, but only for gaps located where radiative transfer is the dominant source of heat (here, a > ~4 AU). In contrast, gaps in viscously-heated regions (a<4 AU) experience a cooler midplane. Outside of the gap, broad radial oscillations in heating and cooling are present. These thermal features affect local segregation of volatile elements (H2O, CH4, CO2, CO) between the dust and gas. We find that icelines — which trace the condensation front inside of which a volatile freezes out — experience significant variations to their paths: deviating up to -6.5 AU vertically and +4.3 AU horizontally from gapless models. In the case of planet-induced gaps, these thermally-driven iceline variations represent a potential feedback from the planet onto the composition of the material it is accreting.