ALMA detection of the rotating molecular disk wind from the young star HD 163296

¹ Leiden Observatory, Leiden University, PO Box 9513 2300 RA, Leiden, The Netherlands
e-mail: klaassen@strw.leidenuniv.nl
² Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile
³ European Southern Observatory, Karl Schwarzschild Str 2, 85748 Garching, Germany
⁴ Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany
⁵ Academia Sinica Institute of Astronomy and Astrophysics, PO Box 23-141, 10617 Taipei, Taiwan
⁶ National Astronomical Observatory of Japan (NAOJ), 2-21-1 Osawa, Mitaka, 181-8588 Tokyo, Japan
⁷ NRAO, 520 Edgemont Road, Charlottesville, VA 22903, USA
⁸ INAF–Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy

Received: 18 January 2013
Accepted: 4 May 2013

Abstract

Disk winds have been postulated as a mechanism for angular momentum release in protostellar systems for decades. HD 163296 is a Herbig Ae star surrounded by a disk and has been shown to host a series of HH knots (HH 409) with bow shocks associated with the farthest knots. Here we present ALMA science verification data of CO J = 2–1 and J = 3–2 emission, which are spatially coincident with the blue shifted jet of HH knots, and offset from the disk by −18.6 km s^-1. The emission has a double corkscrew morphology and extends more than 10′′ from the disk with embedded emission clumps coincident with jet knots. We interpret this double corkscrew as emission from material in a molecular disk wind, and that the compact emission near the jet knots is being heated by the jet that is moving at much higher velocities. We show that the J = 3–2 emission is likely heavily filtered by the interferometer, but the J = 2–1 emission suffers less due to the larger beam and sensitivity to larger scale structures. Excitation analysis suggests temperatures exceeding 900 K in these compact features, with the wind mass, momentum and energy being of order 10^-5 M_⊙, 10^-4 M_⊙ km s^-1 and 10⁴⁰ erg, respectively. The high mass loss rate suggests that this star is dispersing the disk faster than it is funneling mass onto the star.