Decoupled nuclei and nuclear polar rings in regular spiral galaxies . NGC 2841 ?
نویسنده
چکیده
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 perpendicular 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.
منابع مشابه
Far-infrared distributions in nearby spiral galaxies NGC2841 and NGC2976 observed with AKARI/FIS
Far-infrared (IR) images of the nearby Sb galaxy NGC 2841 and the Sc galaxy NGC 2976 at wavelengths of 65, 90, 140, and 160 μm have been obtained with the FarInfrared Surveyor (FIS) onboard AKARI. Both galaxies reveal similar morphologies of dust rings. They are, however, significantly different in the dust temperature: a cold (∼ 21 K) ring for NGC 2841 and a warm (∼ 30 K) ring for NGC 2976, wh...
متن کاملDecoupled Nuclei in the Spiral Galaxies NGC 4216 and NGC 4501
Received ; accepted – 2 – ABSTRACT By using bidimensional spectral data obtained at the 6m telescope for the Virgo spirals NGC 4216 and NGC 4501, we have found chemically distinct metal-rich nuclei in these galaxies. Under the assumption of equal ages for the nuclear and bulge stellar populations, the metallicity difference between the nuclei and their environments in the galaxies is estimated ...
متن کاملLeo II Group : decoupled cores of NGC 3607 and NGC 3608 ⋆
The kinematics, structure, and stellar population properties in the centers of two brightest early-type galaxies of the Leo II group, NGC 3607 and NGC 3608, are studied by means of integral-field spectroscopy. The kinematically distinct areas in the centers of these galaxies, with radii of 6 and 5 respectively, are found also to be chemically distinct. These stellar structures are characterized...
متن کاملTen years of nearby galaxies investigation with the Multi - Pupil Spectrograph of the 6 m telescope Sil ’ chenko Olga
We describe the history and results of our study of early-type disk galaxies with the Multi-Pupil Spectrograph of the 6m telescope (MPFS). With the new data we confirm the discovery of chemically distinct nuclei reported in 1992; now such nuclei are found in two dozens galaxies. The structure of chemically distinct features formed probably in secondary nuclear star-formation bursts seems to be ...
متن کاملDiffuse X-ray Emission from Late-Type Galaxy Haloes
Current theories of galaxy formation predict that spiral galaxies are embedded in a reservoir of hot gas. This gas is able to cool onto the galaxy replenishing cold gas that is consumed in star formation. Estimates of the X-ray luminosity emitted in the cooling region suggest a bolometric luminosity of order 10 × 10 ergs s. We have used ROSAT PSPC data to search for extended X-ray emission from...
متن کامل