Letter to the Editor
Gas infall and possible circumstellar rotation in R Leonis⋆
Molecular Astrophysics Group, Instituto de Física Fundamental, CSIC, C/ Serrano, 123, 28006
2 Observatorio Astronómico Nacional, OAN-IGN, Alfonso XII, 3, 28014 Madrid, Spain
3 Dept. of Space, Earth, and Environment, Astronomy and Plasma Physics Division, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
Accepted: 6 February 2019
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.
Key words: stars: AGB and post-AGB / stars: individual: R Leo / circumstellar matter / stars: mass-loss / techniques: interferometric / techniques: high angular resolution
This paper makes use of the following ALMA data: ADS/JAO.ALMA#2016.1.01202.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ.
© ESO 2019