Distribution and kinematics of neutral hydrogen gas and the radio continuum emission in barred spiral galaxies
VLA radio synthesis observations of three barred spiral galaxies, NGC 1097, NGC 1365, and M83 are presented. Neutral hydrogen spectral line observations were made, as well as continuum observations at wavelengths of 6 cm and 20 cm. The continuum observations of the bars of NGC 1097 and M83 reveal that the radio emission is coincident with the linear dust lanes in the bars, that it is non-thermal in origin, and is moderately polarized. These data show that the dust lanes are generated by shocks, confirming a major theoretical prediction of bar structure. Spectral line observations of the neutral hydrogen gas reveal many interesting properties of these galaxies. Direct observation of the gas flow in the bar of NGC 1097 confirmed the presence of noncircular motions, of similar magnitude, to those predicted based on the presence of the bar and its associated shocks. Noncircular motions in the spiral arms of NGC 1097 and NGC 1365 were also found. The distribution of neutral hydrogen gas in the three galaxies has two common properties. In each galaxy, the peak surface densities of hydrogen gas and the optical spiral arms are coincident. Also, there are rings of gas at radii just larger than the bar lengths in each galaxy, with the greatest concentration of gas occurring at the ends of the bars.
- Research Organization:
- Minnesota Univ., Minneapolis (USA)
- OSTI ID:
- 5733278
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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