Searching for companions down to 2 AU from β Pictoris using the L'-band AGPM coronagraph on VLT/NACO

Context. The orbit of the giant planet discovered around β Pic is slightly inclined with respect to the outer parts of the debris disc, which creates a warp in the inner debris disc. This inclination might be explained by gravitational interactions with other planets.
Aims: We aim to search for additional giant planets located at smaller angular separations from the star.
Methods: We used the new L'-band AGPM coronagraph on VLT/NACO, which provides an exquisite inner working angle. A long observing sequence was obtained on β Pic in pupil-tracking mode. To derive sensitivity limits, the collected images were processed using a principal-component analysis technique specifically tailored to angular differential imaging.
Results: No additional planet is detected down to an angular separation of 0.''2with a sensitivity better than 5 M_Jup. Meaningful upper limits (<10 M_Jup) are derived down to an angular separation of 0.''1, which corresponds to 2 AU at the distance of β Pic.