Catalogue of One-side Head Tail Galaxies in the FIRST Survey

One-side head-tail (OHT) galaxies are radio galaxies with a peculiar shape. They usually appear in galaxy clusters. But they have never been cataloged systematically. We design an automatic procedure to search them in the FIRST (Faint Images of the Radio Sky at Twenty-Centimeters) source catalog and compile a sample with 115 HT candidates. After cross-checking with the SDSS (Sloan Digital Sky Survey) photometric data and catalogs of galaxy clusters, we find that 69 of them are possible OHT galaxies. Most of them are close to the center of galaxy clusters. The lengths of their tails do not correlate with the projection distance to the center of the nearest galaxy clusters, but show weak anti-correlation with the cluster richness, and inversely proportional to the radial velocity differences between clusters and host galaxies. Our catalog provides a unique sample to study this special type of radio galaxies.