resolution than the data presented by [@Ricci2015], which showed tentative evidence of a gap as commented above. This paper is outlined as follows. In §\[sec:obs\] we present the new ALMA observations of the dust continuum and line emission of HD 107146. Then in §\[sec:model\] we model the data using both parametric models and the output of N-body simulations to quantify the disc structure and assess whether a single planet could explain the observations. In §\[sec:dis\] we discuss our results, the origin of the gap and implications for planet formation; the total mass of HD 107146’s outer disc; the detection of an inner component that could be warm dust; and our gas non-detection. Finally the main conclusions of this paper are summarised in §\[sec:conclusions\].

Observations {#sec:obs}
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HD 107146 was observed both in band 7 (0.86mm, project 2016.1.00104.S, PI: S. Marino) and band 6 (1.1mm, project 2016.1.00195.S, PI: J. Carpenter). Band 7 observations were carried out between October and December 2016 (see Table \[tab:obs\]) both using the 12m array and the Atacama Compact Array (ACA) to recover small and large scale structures. The total number of antennas for the 12m array was 42, with baselines ranging from 48 to 410 m 