The Ursa Major cluster of galaxies

IV. HI synthesis observations

¹ NRAO, PO Box O, Socorro, NM 87801, USA
² Kapteyn Institute, Postbus 800, 9700 AV Groningen, The Netherlands
³ Osservatorio Astronomico di Bologna, Via Ranzani 1, 40127 Bologna, Italy

Corresponding author: M. A. W. Verheijen, mverheij@nrao.edu

Received: 15 November 2000
Accepted: 1 December 2000

Abstract

In this data paper we present the results of an extensive 21 cm-line synthesis imaging survey of 43 spiral galaxies in the nearby Ursa Major cluster using the Westerbork Synthesis Radio Telescope. Detailed kinematic information in the form of position-velocity diagrams and rotation curves is presented in an atlas together with HI channel maps, 21 cm continuum maps, global HI profiles, radial HI surface density profiles, integrated HI column density maps, and HI velocity fields. The relation between the corrected global HI linewidth and the rotational velocities and V_flat as derived from the rotation curves is investigated. Inclination angles obtained from the optical axis ratios are compared to those derived from the inclined HI disks and the HI velocity fields. The galaxies were not selected on the basis of their HI content but solely on the basis of their cluster membership and inclination which should be suitable for a kinematic analysis. The observed galaxies provide a well-defined, volume limited and equidistant sample, useful to investigate in detail the statistical properties of the Tully-Fisher relation and the dark matter halos around them.