Comparions of some properties of the HI brightest galaxies
in the southern sky
Figure 3a: Total HI flux vs 50% velocity width.
The two plots below illustrate two of the selection criteria: velocity
width (limited by the channel width) and the HIPASS peak flux.
Figure 3b: Total HI flux vs 50% velocity width.
Zoom-in on Figure 3a.
Figure 3c: 20% velocity width vs 50% velocity width.
The two plots below give some idea of the shape of the HI spectra.
The 20% velocity width is only slightly larger than the 50% velocity width
for typical double horn HI spectra. For Gaussian HI spectra the difference
is slightly more, but for irrgeular galaxies, pairs and groups many different
shapes are observed.
Figure 3d: Total HI flux vs 50% velocity width.
Zoom-in on Figure 3c.
Figure 3e: 50% velocity width vs systemic velocity.
This figure show 50% velocity width in relation to the systemic velocity.
Some trend towards detecting more narrow-width galaxies at higher velocities
is visible. Most of the narrow-width galaxies presumably correspond to more
face-on galaxies).