A comparison of novel algorithms for unbiased recovery of extended disk signals with ADI - Application to the case of MWC 758 and its protoplanet candidates.

With its large sub-mm continuum cavity, asymmetric clumps and spiral arms, the disc of MWC 758 is an ideal test laboratory to search for embedded planets at an early stage of formation and study their dynamical interplay with the disc. As such, two protoplanet candidates have been proposed in this disc by independent teams based on thermal IR high-contrast imaging data, which both require confirmation. In this contribution, I will compare three novel algorithms that we designed to alleviate current shortcomings stemming from the application of state-of-the-art Angular Differential Imaging (ADI)-based algorithms - namely geometric biases induced to azimuthally extended signals from the aggressive modeling and subtraction of the stellar halo. The first algorithm relies on an iterative approach, while the other two rely on an inverse-problem approach, with and without regularisation terms, respectively, to recover the unbiased circumstellar intensity distribution. I will show the images obtained from the application of these algorithms to the case of MWC 758, for which we considered the SPHERE (H23) and NIRC2 (L’) datasets obtained in the best observing conditions for this study. I will then compare these images to predictions from hydro-dynamical simulations testing the hypotheses of a single (internal) eccentric companion, and two giant (internal+external) planets on circular orbits, respectively, and will discuss the likelihood of each scenario based on the similarity to our new images.