Decoupled Nuclei and Nuclear Polar Rings in Regular Spiral Galaxies. NGC 2841

Abstract

The Sb galaxy NGC 2841 was observed at the 6 m telescope of SAO RAS with the Multi-Pupil Field Spectrograph and at the 1 m telescope of SAO RAS with the long-slit spectrograph. An unresolved nucleus of NGC 2841 is shown to be chemically decoupled both in magnesium and in iron with abundance break estimates of 0.36 dex for Mg and 0.6 dex for Fe; an abundance gradient in the bulge is seen only in the magnesium index and is typical for early-type disk galaxies. The rotation axis of the nuclear ionized gas in NGC 2841 is orthogonal to that of the central stellar population; an existence of a bulge stellar component with decoupled rotation momentum in the radius range 5" -12" is suspected. A possible scenario for the origin of the unusual central structure in NGC 2841 is proposed.