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

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 $M_{B_{\rm t}} = -12.85$; linear diameter $A_{0} = 1.63$ kpc (this corresponds to the de Vaucouleurs diameter D25); half power line width $W_{\rm c} = 29$ km s-1; total HI mass $M_{\rm HI} = 2\times 10^{7}~M_{\odot}$; distance $D = 5.1$ Mpc; HI mass-to-luminosity ratio $M_{\rm HI}/L_{B} = 0.9~M_{\odot}/L_{\odot}$; total mass-to luminosity ratio $M_{\rm t}/L_{B} = 2.9~M_{\odot}/L_{\odot}$.