A catalog of H I-selected galaxies from the south celestial cap region of sky

The first deep catalog of the H I Parkes All Sky Survey (HIPASS) is presented, covering the south celestial cap (SCC) region. The SCC area is ∼2400 deg² and covers δ < -62°. The average rms noise for the survey is 13 mJy beam^-1. Five hundred thirty-six galaxies have been cataloged according to their neutral hydrogen content, including 114 galaxies that have no previous cataloged optical counterpart. This is the largest sample of galaxies from a blind H I survey to date. Most galaxies in optically unobscured regions of sky have a visible optical counterpart; however, there is a small population of low-velocity H I clouds without visible optical counterparts whose origins and significance are unclear. The rms accuracy of the HIP ASS positions is found to be 1.′9. The H I mass range of galaxies detected is from ∼10⁶ to ∼10 ¹¹ M⊙. There are a large number of late-type spiral galaxies in the SCC sample (66%), compared with 30% for optically selected galaxies from the same region in the NASA Extragalactic Database. The average ratio of H I mass to B luminosity of the sample increases according to optical type, from 1. 8 M⊙/L⊙ for early types to 3.2 Ṁ/L̇ for late-type galaxies. The H I-detected galaxies tend to follow the large-scale structure traced by galaxies found in optical surveys. From the number of galaxies detected in this region of sky, we predict the full HIPASS catalog will contain ∼5000 galaxies, to a peak flux density limit of ∼39 mJy (3 σ), although this may be a conservative estimate as two large voids are present in the region. The H I mass function for this catalog is presented in a subsequent paper.