The dark halo of the polar-ring galaxy NGC 4650A

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169206· OSTI ID:6304425

Sackett, P D; Sparke, L S ^[1]

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1. Groningen, Rijksuniversiteit (Netherlands) Pittsburgh Univ., PA (USA) Washburn Observatory, Madison WI (USA)

By analyzing the rotation of its central disk and outer polar ring, limits are placed on the flattening of the unseen halo of the galaxy NGC 4650A. A model consisting of a bulge, disk, axisymmetric dark halo, and massive polar ring is fitted to both rotation curves, and it is shown that the observations are consistent with a range of halo flattening, from spherical to as flat as an E8 elliptical galaxy. The best fits are obtained for dark halo flattenings in the range E3-E7. The substantial mass of the ring is probably responsible for a characteristic wiggle in the polar rotation curve; fits to this feature suggest that there may be considerably more mass in the ring than has been reported from neutral hydrogen measurements. 30 refs.

• OSTI ID: 6304425
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 361; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BALMER LINES
CONFIGURATION
ELLIPTICAL CONFIGURATION
GALAXIES
LIMITING VALUES
MASS
MATHEMATICAL MODELS
MORPHOLOGY
MOTION
NONLUMINOUS MATTER
ROTATION