HI observations of nearby galaxies V. Narrow (HI) line galaxies

Abstract

In this paper we present new HI observations with high velocity resolution for 104 nearby narrow-line galaxies with half power line widths smaller than 50 km s-1 most of which are well approximated by a Gaussian. The FWHM line width of 30 of these integrated HI profiles is less than 25 km s-1. We present global parameters of these nearby galaxies and discuss the size dependence, the luminosity dependence, and the dependence of these parameters with the observed line width. Our sample essentially is a subsample of the Local Volume (i.e. galaxies within 10 Mpc) with declinations ≥-30° and only a few galaxies at greater distances. It is described by the following median values of global physical parameters: total absolute blue magnitude ; linear diameter kpc (this corresponds to the de Vaucouleurs diameter D25); half power line width km s-1; total HI mass ; distance Mpc; HI mass-to-luminosity ratio ; total mass-to luminosity ratio .