ALMA discovery of a rotating SO/SO₂ flow in HH212

A possible MHD disk wind?

¹ LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Université, UPMC Univ. Paris 06, 75014 Paris, France
e-mail: benoit.tabone@obspm.fr
² Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
³ INAF, Osservatorio Astrofisico di Arceti, Largo E. Fermi 5, 50125 Firenze, Italy
⁴ Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, via G. Sansone 1, 50019 Sesto Fiorentino, Italy
⁵ Institut d’Astrophysique Spatiale, CNRS UMR 8617, Université Paris-Sud, 91405 Orsay, France
⁶ Institut de Radioastronomie Millimétrique, 38406 Saint-Martin d’ Hères, France
⁷ OASU/LAB-UMR5804, CNRS, Université Bordeaux, 33615 Pessac, France

Received: 1 August 2017
Accepted: 29 September 2017

Abstract

We wish to constrain the possible contribution of a magnetohydrodynamic disk wind (DW) to the HH212 molecular jet. We mapped the flow base with ALMA Cycle 4 at 0.̋13 ~ 60 au resolution and compared these observations with synthetic DW predictions. We identified, in SO/SO₂, a rotating flow that is wider and slower than the axial SiO jet. The broad outflow cavity seen in C³⁴S is not carved by a fast wide-angle wind but by this slower agent. Rotation signatures may be fitted by a DW of a moderate lever arm launched out to ~40 au with SiO tracing dust-free streamlines from 0.05−0.3 au. Such a DW could limit the core-to-star efficiency to ≤50%.