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Kinematic structure of the 30 Doradus giant H II regionWe have used the echelle CCD spectrograph on the Cerro Tololo Inter-American Observatory (CTIO) 4 m telescope to map the nebular velocity field in the 30 Doradus giant H II region. The kinematics of 30 Dor are very complex. The outer regions are charaterized by a smooth velocity field, but its turbulent velocity, 30-40 km/s Full Width Half Maximum (FWHM), is considerably higher than those in most smaller H II regions. In the central 9 min core, multiple velocity components are observed at most positions. The velocity field is dominated by a large number of expanding structures, ranging in size from 1 to 100 pc and expansion velocities of 20-200 km/s, and often organized into large hierarchical networks. The integral of these complex expanding structures in 30 Dor produces a surprisingly simple profile with a broad Gaussian core and faint extended wings. Several fast-expanding shells, with diameters of 2-20 pc, expansion velocities of 100-300 km/s, and kinetic energies of 0.5-10 x 10(exp 50) ergs have been identified. The large fast-expanding shells and networks are coincident with extended X-ray sources and are probably associated with supernova remnants embedded in supershells produced by the combined effects of stellar winds and supernovae from OB associations. We have used the intensity-calibrated echelle spectra to determine the basic physical and dynamical properties of the kinematic features in 30 Dor. The expanding shells contain roughly half of the kinetic energy in the 30 Dor complex, and this energy is several times higher than the gravitational binding energy of the region. The energetic requirements of the gas are consistent with the observed stellar content of 30 Dor, if the gas is accelerated by a combination of stellar winds and supernovae. Extrapolating the current energy injection rate in the nebula over the lifetime of the OB complex suggest that 30 Dor and its vicinity will evolve into a supergiant shell as seen in the LMC and other nearby galaxies.
Document ID
19950037928
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Chu, You-Hua
(Univ. of Illinois at Urbana-Champaign, Urbana, IL United States)
Kennicutt, Robert C., Jr.
(Univ. of Arizona, Tucson, AZ United States)
Date Acquired
August 16, 2013
Publication Date
April 20, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 425
Issue: 2
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A69527
Funding Number(s)
CONTRACT_GRANT: NAG5-1900
CONTRACT_GRANT: NSF AST-90-19150
CONTRACT_GRANT: NAG5-2112
Distribution Limits
Public
Copyright
Other

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