Gas infall and possible circumstellar rotation in R Leonis

Abstract

We present new interferometer molecular observations of R Leo taken at 1.2 mm with the Atacama Large Millimeter Array with an angular resolution up to ≃0.″026. These observations permitted us to resolve the innermost envelope of this star, which revealed a complex structure that involves extended continuum emission and molecular emission showing a non-radial gas velocity distribution. This molecular emission displays prominent red-shifted absorptions located immediately in front of the star, which are typical footprints of material infall. This emission also shows lateral gas motions compatible with a torus-like structure.