Stars and ionized gas in S0 galaxy NGC 7743: an inclined large-scale gaseous disk

Abstract

We used deep long-slit spectra and integral-field spectral data to study the stars and ionized gas kinematics and stellar population properties in the lenticular barred galaxy NGC 7743. We have shown that ionized gas at the distances larger than 1.5 kpc from the nucleus settles in the disk which is significantly inclined to the stellar disk of the galaxy. Making different assumptions about the geometry of the disks and involving different sets of emission lines into the fitting, under the assumption of thin flat disk circular rotation, we obtain the full possible range of angle between the disks to be 34+/-9 or 77+/-9 deg. The most probable origin of the inclined disk is the external gas accretion from a satellite, orbiting the host galaxy with a corresponding angular momentum direction. The published data on the HI distribution around NGC 7743 suggest that the galaxy has a gas-rich environment. The emission-line ratio diagrams imply the domination of shock waves in the ionization state of the gaseous disk, whereas the contribution of photoionization by recent star formation seems to be negligible. In some parts of the disk a difference between the velocities of the gas emitting in the forbidden lines and in the Balmer lines is detected. It may be caused by the fact that the inclined disk is mainly shock-excited, whereas some fraction of the Balmer-line emission is produced by a small amount of gas excited by young stars in the main stellar disk of NGC 7743. In the circumnuclear region (R< 200 pc) some evidences of the AGN jet interaction with an ambient interstellar medium were found.

11 pages, 7 figures, accepted by Astrophysical Journal

References in corpus (11)

• The Atlas3D project -- I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria
• The MAPPINGS III Library of Fast Radiative Shock Models
• The Outer Disks of Early-Type Galaxies. I. Surface-Brightness Profiles of Barred Galaxies
• Properties of Bars and Bulges in the Hubble Sequence
• Spectroscopic ages and metallicities of stellar populations: validation of full spectrum fitting
• Spectral Variability of LBV star V532 (Romano's star)
• Seyfert galaxies that are undergoing merging but appear non-interacting
• Sigma-drop in galaxies and the sigma-metallicity degeneracy
• The search for inner polar disks with integral field spectroscopy: the case of NGC 2855 and NGC 7049
• A new sky subtraction technique for low surface brightness data
• Star Formation History at the Centers of Lenticular Galaxies with Bars and Purely Exponential Outer Disks from SAURON Data

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• A search for ionised gas outflows in an Halpha imaging atlas of nearby LINERs
• Tilted outer and inner structures in edge-on galaxies?
• Are polar rings indeed polar?
• Stellar nuclei and inner polar disks in lenticular galaxies
• A Ringed Dwarf LINER 1 Galaxy Hosting an Intermediate-mass Black Hole with Large-scale Rotation-like Hα Emission
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