Characterizing the radial oxygen abundance distribution in disk galaxies
Abstract
Context. The relation between the radial oxygen abundance distribution (gradient) and other parameters of a galaxy such as mass, Hubble type, and a bar strength, remains unclear although a large amount of observational data have been obtained in the past years.
Aims: We examine the possible dependence of the radial oxygen abundance distribution on non-axisymmetrical structures (bar/spirals) and other macroscopic parameters such as the mass, the optical radius R25, the color g - r, and the surface brightness of the galaxy. A sample of disk galaxies from the third data release of the Calar Alto Legacy Integral Field Area Survey (CALIFA DR3) is considered.
Methods: We adopted the Fourier amplitude A2 of the surface brightness as a quantitative characteristic of the strength of non-axisymmetric structures in a galactic disk, in addition to the commonly used morphologic division for A, AB, and B types based on the Hubble classification. To distinguish changes in local oxygen abundance caused by the non-axisymmetrical structures, the multiparametric mass-metallicity relation was constructed as a function of parameters such as the bar/spiral pattern strength, the disk size, color index g - r in the Sloan Digital Sky Survey (SDSS) bands, and central surface brightness of the disk. The gas-phase oxygen abundance gradient is determined by using the R calibration.
Results: We find that there is no significant impact of the non-axisymmetric structures such as a bar and/or spiral patterns on the local oxygen abundance and radial oxygen abundance gradient of disk galaxies. Galaxies with higher mass, however, exhibit flatter oxygen abundance gradients in units of dex/kpc, but this effect is significantly less prominent for the oxygen abundance gradients in units of dex/R25 and almost disappears when the inner parts are avoided (R > 0.25R25). We show that the oxygen abundance in the central part of the galaxy depends neither on the optical radius R25 nor on the color g - r or the surface brightness of the galaxy. Instead, outside the central part of the galaxy, the oxygen abundance increases with g - r value and central surface brightness of the disk.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 2019
- DOI:
- 10.1051/0004-6361/201834364
- arXiv:
- arXiv:1810.08006
- Bibcode:
- 2019A&A...623A...7Z
- Keywords:
-
- galaxies: abundances;
- ISM: abundances;
- H II regions;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 11 pages, 6 figures