Ionised gas abundances in barred spiral galaxies

Abstract

This is the third paper of a series devoted to study the properties of bars from long slit spectroscopy to understand their formation, evolution and their influence on the evolution of disk galaxies. In this work we aim to determine the gas metallicity distribution of a sample of 20 barred early-type galaxies. We compare the nebular and stellar metallicity distributions to conclude about the origin of the warm gas. We compare the results of nebular emission metallicities using different semi-empirical methods. We carry out AGN diagnostic diagrams along the radius to determine the radius of influence of the AGN and the nuclei nature of the studied galaxies. We then derive the gas metallicities along the bars and compare the results to the distribution of stellar metallicities in the same regions. Most of the gas emission is centrally concentrated, although 15 galaxies also show emission along the bar. In the central regions, gas oxygen abundances are in the range 12+$\log$(O/H)= 8.4-9.1. The nebular metallicity gradients are very shallow in the bulge and bar regions. For three galaxies (one of them a LINER), the gas metallicities lie well below the stellar ones in the bulge region. These results do not depend on the choice of the semi-empirical calibration used to calculate the abundances. We see that the galaxies with the lowest abundances are those with the largest rotational velocities. The presence of gas of significantly lower metallicity than the stellar abundances in three of our galaxies, points to an external origin as the source of the gas that fuels the present star formation in the centre of some early-type barred galaxies. The fact that the bar/disk nebular metallicities are higher than the central ones might be indicating that the gas could be accreted via cooling flows instead of radial accretion from gas sitting in the outer parts of the disk.

20 pages, 15 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (17)

• The Host Galaxies and Classification of Active Galactic Nuclei
• The relation between metallicity, stellar mass and star formation in galaxies: an analysis of observational and model data
• The impact of gas inflows on star formation rates and metallicities in barred galaxies
• Star formation history of barred disc galaxies
• The oxygen abundance in the inner HII regions of M101. Implications for the calibration of strong-line metallicity indicators
• Stellar Population and Kinematic Profiles in Spiral Bulges & Disks: Population Synthesis of Integrated Spectra
• Neon and Argon optical emission lines in ionized gaseous nebulae: Implications and applications
• The Kinematics of Thick Disks in Nine External Galaxies
• Fourier Dissection of Early-Type Galaxy Bars
• Star formation in isolated AMIGA galaxies: dynamical influence of bars
• The chemical evolution of a Milky Way-like galaxy: the importance of a cosmologically motivated infall law
• Nearby early-type galaxies with ionized gas. The UV emission from GALEX observations
• Study of stellar populations in the bulges of barred galaxies
• An Introduction to Galactic Chemical Evolution
• New light on the formation and evolution of bars: Trends in the stellar line-strength indices distribution inside the bar region
• Reexamination of the Radial Abundance Gradient Break in NGC 3359
• A method to resolve the nuclear activity in galaxies, as applied to NGC1358

Cited by in corpus (6)

• The physics of gas phase metallicity gradients in galaxies
• The VIRUS-P Exploration of Nearby Galaxies (VENGA): Spatially Resolved Gas-Phase Metallicity Distributions in Barred and Unbarred Spirals
• LeMMINGs. II. The e-MERLIN legacy survey of nearby galaxies. The deepest radio view of the Palomar sample on parsec scale
• Central enhancement of the nitrogen-to-oxygen abundance ratio in barred galaxies
• Circumnuclear rings and Lindblad resonances in spiral galaxies
• Chemical Abundance of the LINER galaxy UGC 4805 with SDSS-IV MaNGA