CO Images of the Central Regions of 20 Nearby Spiral Galaxies

摘要: We report a CO(J = 1-0) aperture-synthesis survey of the central regions 20 nearby spiral galaxies. The sample is selected on basis inclination, single-dish CO flux, and lack significant dynamical perturbation. No selection made their nuclear activity, starburst, or infrared luminosity. observations have been using Nobeyama Owens Valley millimeter arrays, with typical resolutions 4'' (300 pc) km s-1, sensitivities ~30 mJy beam-1 for s-1 channel. In this paper, we present integrated intensity mean velocity maps, azimuthally averaged radial distributions, position-velocity plots. Most galaxies in scale lengths distribution that are much smaller than outer disks. Typically, emission falls to 1/e peak value at radii ~500 pc. This significantly global distributions galactic diagrams exhibit steep rise rotation velocity, dV/dr ~ 1 pc-1, most line width typically reaches ~95% overall H I within radius kpc. mainly reflects highly concentrated mass centers, though it may well be partly due noncircular motions barred number galaxies, show small hole (d 100 emission. many detect clumps subkiloparsec size which giant molecular associations (GMAs). Appendix, demonstrate holes center can readily detected even when they spatial resolution data.