| Title | High-Resolution, High Signal-to-Noise, Global H i Spectra of Southern, Extreme Late-Type Spiral Galaxies |
| Authors | Matthews, L. D.; van Driel, W.; Gallagher, J. S., III |
| Bibcode | 1998AJ....116.1169M Search ADS ↗ |
| Abstract | We have used the Nançay decimetric radio telescope to obtain high-resolution, high signal-to-noise, global H i spectra of 30 southern, extreme late-type spiral galaxies with V_h <= 3000 km s^-1. For all of the galaxies we measure new precise radial velocities and H i velocity widths. Optical imaging and photometry of these galaxies was recently published by Matthews & Gallagher. In Appendix B we present new H i spectra for four additional late-type galaxies. The H i spectra of the extreme late-type spirals have velocity widths characteristic of true, rotationally supported disk galaxies, and most are double-peaked. Nonetheless, the morphologies of the H i profiles are diverse, indicating that disk galaxies with similar H i contents and optical luminosities can have very different H i distributions and/or velocity fields. H i profile type and Hubble type are generally well-correlated for our sample. Seventy-seven percent of our H i profiles show at least some degree of asymmetry; in many cases the stellar disk of these galaxies is also asymmetric. Several of our spectra have an additional H i peak near the systemic velocity, perhaps indicating a gas enhancement in the central regions of the galaxy disk. |
| Objects | 38 Objects Search NED ↙ |
