The search for inner polar disks with integral field spectroscopy: the case of NGC 2855 and NGC 7049^*

¹ Kapteyn Astronomical Institute, University of Groningen, Postbus 800, 9700 AV Groningen, The Netherlands e-mail: coccato@astro.rug.nl
² Dipartimento di Astronomia, Università di Padova, vicolo dell'Osservatorio 3, 35122 Padova, Italy
³ Scuola Galileiana di Studi Superiori, via VIII Febbraio 2, 35122 Padova, Italy

Received: 8 August 2006
Accepted: 11 January 2007

Abstract

Context.The presence of non-circular and off-plane gas motion is frequently observed in the inner regions of disk galaxies.

Aims.With integral-field spectroscopy we have measured the surface-brightness distribution and kinematics of the ionized gas in NGC 2855 and NGC 7049. These two early-type spiral galaxies were selected as possibly hosting a kinematically-decoupled gaseous component in orthogonal rotation with respect to the galaxy disk.

Methods.We have modeled the ionized-gas kinematics and distribution of both galaxies assuming that the gaseous component is distributed either on two orthogonally-rotating disks or in a single and strongly warped disk.

Results.In both galaxies the velocity field and distribution of the inner gas are consistent with the presence of an inner polar disk. In NGC 2855 it correponds to the innermost and strongly warped portion of the main disk. In NGC 7049 it is a central and geometrically-decoupled disk, which is nested in the main disk.