Two monodisperse setups for St = 0.1 (left) and St = 0.889 (right). Top five rows: Three different planet masses (1.5, 4.7, and 10 M_⊕), denoted by colour. The dotted lines signify a static (as opposed to evolving) gas disc. The planet is situated at a_pl = 1 AU. Back-reaction is disabled for these results. First row : azimuthally averaged gas surface density. Second row : azimuthally averaged pebble surface density. Third row : total radial pebble mass flow, as described in Eq. (17). Fourth row : total radial gas flow. Fifth row : dimensionless η-parameter relating v_g,φ and v_κ, as in Eqs. (8) and (9). Bottom plots : pebble streamlines for a static (left), and an evolving disc (right) for a 10 M_⊕ planet. These pebble lines are indicated by the grey lines in the azimuthally averaged and/or summed graphs above. The dash-dotted circle indicates the Hill sphere. The arrows on the right plots illustrating the evolving gas disc signify the direction of the horseshoe orbits. Pebble streamlines arise in the outer disc, with the darker ones accreting onto the planet. The accreting fraction for an evolving gas disc is higher by approximately 16% for St = 0.1 and lower by approximately 12% for St = 0.889.