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.

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

CORSINI, ENRICO MARIA;PIZZELLA, ALESSANDRO;BERTOLA, FRANCESCO
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.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2430251
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 10
  • ???jsp.display-item.citation.isi??? 11
social impact