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Title: KINEMATICS OF THE OUTFLOW FROM THE YOUNG STAR DG TAU B: ROTATION IN THE VICINITIES OF AN OPTICAL JET

We present {sup 12}CO(2-1) line and 1300 μm continuum observations made with the Submillimeter Array of the young star DG Tau B. We find, in the continuum observations, emission arising from the circumstellar disk surrounding DG Tau B. The {sup 12}CO(2-1) line observations, on the other hand, revealed emission associated with the disk and the asymmetric outflow related with this source. Velocity asymmetries about the flow axis are found over the entire length of the flow. The amplitude of the velocity differences is of the order of 1-2 km s{sup –1} over distances of about 300-400 AU. We interpret them as a result of outflow rotation. The sense of the outflow and disk rotation is the same. Infalling gas from a rotating molecular core cannot explain the observed velocity gradient within the flow. Magneto-centrifugal disk winds or photoevaporated disk winds can produce the observed rotational speeds if they are ejected from a Keplerian disk at radii of several tens of AU. Nevertheless, these slow winds ejected from large radii are not very massive, and cannot account for the observed linear momentum and angular momentum rates of the molecular flow. Thus, the observed flow is probably entrained material from the parentmore » cloud. DG Tau B is a good laboratory to model in detail the entrainment process and see if it can account for the observed angular momentum.« less
Authors:
; ; ; ;  [1] ;  [2] ;  [3]
  1. Centro de Radioastronomía y Astrofísica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Mich. (Mexico)
  2. Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan (China)
  3. Astronomy Department, University of Illinois, 1002 West Green Street, Urbana, IL 61801 (United States)
Publication Date:
OSTI Identifier:
22364613
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 798; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AMPLITUDES; ANGULAR MOMENTUM; ASYMMETRY; CARBON MONOXIDE; CLOUDS; DISTANCE; JETS; LINEAR MOMENTUM; PHOTON EMISSION; ROTATION; STARS; STELLAR WINDS; VELOCITY