NGC 1058 - Gas motions in an extended, quiescent spiral disk

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168555· OSTI ID:6865193

Dickey, J M; Hanson, M M; Helou, G ^[1]

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1. Minnesota Univ., Minneapolis (USA) Leiden Rijksuniversiteit, Sterrewacht (Netherlands) Colorado Univ., Boulder (USA) California Institute of Technology, Pasadena (USA)

The motion of gas in the galaxy NGC 1058 is examined, using VLA observations to map emission in the 21-cm line. The hypothesis that the rotation curve drops faster than Keplerian at the outer edge of the disk is confirmed. It is found that the line width decreases with optical surface brightness, but in the extended gas disk beyond the Holmberg radius, the line width is constant. The observations show no correlation between line width and spiral phase of H I surface density in the outer disk. Evidence is found for an intermediate velocity cloud population with a velocity width several times broader than that of the bulk of the H I in the optically bright disk. 29 refs.

• OSTI ID: 6865193
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 352; 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
CONFIGURATION
COSMIC GASES
COSMIC RADIO SOURCES
DENSITY
DYNAMICS
ELECTROMAGNETIC RADIATION
FLUIDS
GALAXIES
GASES
H1 REGIONS
LINE WIDTHS
MECHANICS
MOTION
PHYSICAL PROPERTIES
RADIATIONS
RADIOWAVE RADIATION
ROTATION
SPIRAL CONFIGURATION
VELOCITY