HI-rich dwarf galaxies in the Hydra I cluster^*

II. Spectroscopic data

¹ CNRS URA 2052 and CEA, DSM, DAPNIA, Service d'astrophysique, 91191 Gif-sur-Yvette Cedex, France
² Observatoire de Paris, DAEC, UMR 8631, CNRS and Université Paris 7, 92195 Meudon Cedex, France
³ Astronomy Department, University of Virginia, Charlottesville, VA 22903, USA
⁴ Universitäts-Sternwarte, Geismarlandstr. 11, 37083 Göttingen, Germany
⁵ Unité Scientifique Nançay, CNRS USR B704, Observatoire de Paris, 92195 Meudon Cedex, France

Corresponding author: P.-A. Duc, paduc@cea.fr

Received: 8 December 2000
Accepted: 18 January 2001

Abstract

We present spectrophotometric data for a sample of 15 HI-selected dwarf galaxies in the Hydra I cluster (see Duc et al. 1999, Paper I). Long-slit spectra were obtained along an axis including the nucleus and the brightest HII region in each galaxy. The oxygen abundance was estimated from the emission lines using various methods. All dwarfs host one or several star-forming regions that are, for the most part, located outside the nucleus. We did not find in this survey any extremely metal-deficient objects, but we did observe some galaxies with a surprisingly high metallicity for their luminosity. In a following paper in this series, we will discuss the global properties of the HI-rich dwarfs in the Hydra I cluster and focus on their dependence on the environment.