Quantitative interpretation of the rotation curves of spiral galaxies at redshifts z ~ 0.7 and z ~ 1

¹ Astronomisches Rechen-Institut, Mönchhofstraße 12-14, 69120 Heidelberg, Germany e-mail: fuchs@ari.uni-heidelberg.de
² Universitätssternwarte Göttingen, Geismarlandstraße 11, 37083 Göttingen, Germany
³ Landessternwarte Heidelberg, Königstuhl, 69117 Heidelberg, Germany

Received: 5 April 2004
Accepted: 17 July 2004

Abstract

We present decompositions of the rotation curves of three spiral galaxies at redshifts 0.7 and 1 into contributions by their bulges, disks, and dark halos, respectively. In order to set constraints on the degeneracy of the decompositions we interpret the morphology of the spiral structures quantitatively in the framework of density wave theory. Galaxy models constrained in such a way show that the distant galaxies, which are much younger than nearby galaxies, have very likely “maximum disks”, i.e. are dominated in their inner parts by baryonic matter. We argue that current theories of the cosmogony of galaxies must allow for these types of galaxies.