ALMA detection of the rotating molecular disk wind from the young star HD 163296
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.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 2013
- DOI:
- arXiv:
- arXiv:1304.5436
- Bibcode:
- 2013A&A...555A..73K
- Keywords:
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- stars: pre-main sequence;
- ISM: jets and outflows;
- ISM: kinematics and;
- dynamics;
- stars: individual: HD 163296;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication in A&