Parkes H I observations of galaxies behind the southern Milky Way^*

I. The Hydra/Antlia region ( 266 to 296)

¹ Depto. de Astronomía, Universidad de Guanajuato, Apartado Postal 144, Guanajuato, Gto 36000, Mexico
² Institute for Astrophysics, University of New Mexico, 800 Yale Blvd., NE, Albuquerque, NM 87131, USA
³ Dept. of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK

Corresponding author: R. C. Kraan-Korteweg, kraan@astro.ugto.mx

Received: 3 April 2002
Accepted: 11 June 2002

Abstract

As part of our program to map the large-scale distribution of galaxies behind the Milky Way, we used the Parkes 210 ft (64 m) radio telescope for pointed  observations of a sample of low surface-brightness (due to heavy obscuration) spiral galaxies selected from the deep optical Zone of Avoidance (ZOA) galaxy catalog in the Hydra/Antlia region (Kraan-Korteweg [CITE]). Searching a simultaneous velocity range of either 300 to 5500 km s^-1 or 300 to 10 500 km s^-1 to an rms level of typically 2–4 m Jy resulted in detections in 61 of the 139 pointings, leading to a total of 66 detections (an additional detection was made in a reference position, and two other pointings revealed two and four independent signals respectively). Except for 2 strong  emitters identified in the shallow Zone of Avoidance  survey (Henning et al. [CITE]), all  detections are new. An analysis of the properties of the observed and detected galaxies prove that pointed  observations of highly obscured galaxies allow the tracing of a population of nearby, intrinsically large and bright spiral galaxies that otherwise would not be recovered. The new data identified a previously unrecognized nearby group at  km s^-1, the continuation of the Hydra/Antlia filament on the opposite side of the Galactic plane, and helped to delimit a distinct void in the ZOA centered at 2000 km s^-1.