Abstract
view Abstract Citations (59) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Dynamical Models of the Barred Spiral Galaxy NGC 3992 Hunter, J. H., Jr. ; Ball, R. ; Huntley, J. M. ; England, Martin N. ; Gottesman, S. T. Abstract In this paper we construct dynamical models that partially reproduce observations of H I in the barred spiral galaxy NGC 3992. The models are constrained by the large-scale structure and kinematics of the gas (Paper I) and by the near-infrared morphology of the bar. The dynamical components we have considered consist of (1) an axisymmetric Toomre disk of index n = 0, truncated as indicated in Paper I; (2) a triaxial stellar bar constrained by near-infrared photometry; (3) an oval distortion of the axisymmetric disk; and (4) a spherical halo constrained by the observed kinematics and truncation of the disk (Paper I). The gas response to all or combinations of these components was investigated using the "beam scheme," hydrodynamical procedure. The strength of this approach, within the limitations of our observations, is considered in detail. Owing to the presence of the central bisymmetry, each promising model had to be projected into the same orientation as the galaxy and then convolved with a synthetic antenna response. Only in this fashion could model and observation be compared properly. The disk and halo components were chosen to give circular velocities in agreement with the H I kinematics. An oval distortion and/or a bar were added to produce both the observed, central deficiency in the gas and the systematic kinematic phenomena in the bar zone (the kinematic offset). The oval distortion controls the gas response at large radii, but, in addition, a triaxial bar, with a mass of 18%-30% of the disk, must exist at the center of NGC 3992. This latter element produces the central depression and kinematic offset in the gas. Corotation of the total bisymmetric component must occur at the radius of the bar. Also we find that a halo must surround the galaxy, containing a mass roughly equivalent to that of the disk interior to the disk radius. We find our models suffer the major shortcoming that the gas arms of the models do not coincide with the tightly wound, star-formation arms that are observed. Either the dynamics of our models are incomplete, or nondynamical causes are important to the present configuration of the arms. Publication: The Astrophysical Journal Pub Date: January 1988 DOI: 10.1086/165932 Bibcode: 1988ApJ...324..721H Keywords: Barred Galaxies; Dynamic Models; Galactic Structure; H I Regions; Extragalactic Radio Sources; Halos; Hydrogen Clouds; Morphology; Astrophysics; GALAXIES: INDIVIDUAL NGC NUMBER: NGC 3992; GALAXIES: INTERNAL MOTIONS; GALAXIES: STRUCTURE; RADIO SOURCES: 21 CM RADIATION full text sources ADS | data products SIMBAD (2) NED (2)
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