Carbon, nitrogen and oxygen abundance gradients in M101 and M31

Abstract

We present deep spectrophotometry of 18 HII regions in the nearby massive spiral galaxies M101 and M31. We have obtained direct determinations of electron temperature in all the nebulae. We detect the CII 4267 line in several HII regions, permitting to derive the radial gradient of C/H in both galaxies. We also determine the radial gradients of O/H, N/O, Ne/O, S/O, Cl/O and Ar/O ratios. As in other spiral galaxies, the C/H gradients are steeper than those of O/H producing negative slopes of the C/O gradient. The scatter of the abundances of O with respect to the gradient fittings do not support the presence of significant chemical inhomogeneities across the discs of the galaxies, especially in the case of M101. We find trends in the S/O, Cl/O and Ar/O ratios as a function of O/H in M101 that can be reduced using Te indicators different from the standard ones for calculating some ionic abundances. The distribution of the N/O ratio with respect to O/H is rather flat in M31, similarly to previous findings for the MilkyWay. Using the disc effective radius, Re, as a normalization parameter for comparing gradients, we find that the latest estimates of Re for the Milky Way provide an excess of metallicity in apparent contradiction with the mass-metallicity relation; a value about two times larger might solve the problem. Finally, using different abundance ratios diagrams we find that the enrichment timescales of C and N result to be fairly similar despite their different nucleosynthetic origin.

arXiv comment20 pages, 17 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (45)

• Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
• PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results
• The chemical composition of metal-poor emission-line galaxies in the Data Release 3 of the Sloan Digital Sky Survey
• A characteristic oxygen abundance gradient in galaxy disks unveiled with CALIFA
• The Composition Gradient in M101 Revisited. II. Electron Temperatures and Implications for the Nebular Abundance Scale
• The Evolution of Isotope Ratios in the Milky Way Galaxy
• On The Cosmic Origins Of Carbon And Nitrogen
• Oxygen and nitrogen abundances in nearby galaxies. Correlations between oxygen abundance and macroscopic properties
• SDSS IV MaNGA - Metallicity and nitrogen abundance gradients in local galaxies
• Does the Milky Way have a Maximal Disk?
• The Luminosity Profile and Structural Parameters of the Andromeda Galaxy
• Integral field spectroscopy of a sample of nearby galaxies: II. Properties of the H ii regions
• A wide-field HI mosaic of Messier 31. II.The disk warp, rotation and the dark matter halo
• The localized chemical pollution in NGC 5253 revisited: Results from deep echelle spectrophotometry
• The ionizing stars of extragalactic H II regions
• The Chemical Composition of the 30 Doradus Nebula Derived from VLT Echelle Spectrophotometry
• The oxygen abundance in the inner HII regions of M101. Implications for the calibration of strong-line metallicity indicators
• Electron impact excitation of OII fine-structure levels
• Nitrogen and oxygen abundances in the Local Universe
• Radial distribution of dust, stars, gas, and star-formation rate in DustPedia face-on galaxies
• Chemical abundances in M31 from HII regions
• Collision Strengths for [O III] Optical and Infrared Lines
• Yields of rotating stars at solar metallicity
• Carbon in Spiral Galaxies from Hubble Space Telescope Spectroscopy
• Temperature Bias and the Primordial Helium Abundance Determination
• PPAK Wide-field Integral Field Spectroscopy of NGC 628: II. Emission line abundance analysis
• Optical Recombination Lines of Heavy-elements in Giant Extragalactic HII Regions
• The distance to the Andromeda Galaxy from eclipsing binaries
• Corrigendum: Improved He~I Emissivities in the Case B Approximation
• Carbon and oxygen in HII regions of the Magellanic Clouds: abundance discrepancy and chemical evolution
• Testing CNO Enrichment Scenarios in Metal-poor Galaxies with HST Spectroscopy
• The [Fe IV] Discrepancy: Constraining the Iron Abundances in Nebulae
• BOND: Bayesian Oxygen and Nitrogen abundance Determinations in giant H II regions using strong and semi-strong lines
• Evolution over time of the Milky Way's disc shape
• Revisiting the radial abundance gradients of nitrogen and oxygen of the Milky Way
• Carbon and oxygen abundance gradients in NGC300 and M33 from optical recombination lines
• NGC 2579 and the carbon and oxygen abundance gradients beyond the solar circle
• Testing For Azimuthal Abundance Gradients In M101
• The radial abundance gradient of oxygen towards the Galactic anticentre
• VLT Echelle Spectrophotometry of the Planetary Nebula NGC 5307 and Temperature Variations
• Star formation and stellar populations in the Wolf-Rayet(?) luminous compact blue galaxy IRAS 08339+6517
• Chemical Abundances of Planetary Nebulae in the Substructures of M31
• The abundance discrepancy in H II regions
• Deep high spectral resolution spectroscopy and chemical composition of ionized nebulae
• Chemical abundances and temperature structure of H II regions

Cited by in corpus (29)

• Characterizing Extreme Emission Line Galaxies I: A Four-Zone Ionization Model for Very-High-Ionization Emission
• The Galactic radial abundance gradients of C, N, O, Ne, S, Cl and Ar from deep spectra of H II regions
• CHAOS VI: Direct Abundances in NGC 2403
• Gradients of chemical abundances in the Milky Way from HII regions: distances derived from Gaia EDR3 parallaxes and temperature inhomogeneities
• Chemical abundances of Seyfert 2 AGNs-III. Reducing the oxygen abundance discrepancy
• Temperature inhomogeneities cause the abundance discrepancy in H II regions
• Density biases and temperature relations for DESIRED HII regions
• On the radial abundance gradients of nitrogen and oxygen in the inner Galactic disc
• CHAOS VII: A Large-Scale Direct Abundance Study in M33
• Chemical abundances in 7 metal-poor HII regions and a determination of the primordial helium abundance
• Light Elements in the Universe
• Bar effect on gas-phase abundance gradients. I. Data sample and chemical abundances
• About Metallicity Variations in the Local Galactic Interstellar Medium
• The Red Supergiant Binary Fraction as a Function of Metallicity in M31 and M33
• The homogeneity of chemical abundances in H II regions of the Magellanic Clouds
• The survey of planetary nebulae in Andromeda (M31). IV. Radial oxygen and argon abundance gradients of the thin and thicker disc
• A spectroscopic study of blue supergiant stars in Local Group spiral galaxies: Andromeda and Triangulum
• Atomic Data Assessment with PyNeb: Radiative and Electron Impact Excitation Rates for [Fe II] and [Fe III]
• CHAOS V: Recombination Line Carbon Abundances in M101
• New calibrations for estimating the N/O ratio in HII regions
• Breaking the degeneracy between gas inflow and outflows with stellar metallicity: Insights on M101
• Extended MCDHF calculations of energy levels and transition data for N I
• Investigating the Origin of Observed Central Dips in Radial Metallicity Profiles
• Star Cluster Formation and Evolution in M101: An Investigation with the Legacy Extragalactic UV Survey
• Spatially-resolved properties of the ionized gas in the HII galaxy J084220+115000
• Mass-dependent chemical enrichment sequences of SDSS star-forming galaxies out to z~0.3 revealed by direct O & Ar abundances
• SDSS-V LVM: A spatially resolved study of the physical conditions and the chemical abundance discrepancy in the Lagoon Nebula (M 8)
• When Stars Mimic Monsters: Spectral Evidence for an $\eta$ Carinae-like Giant Eruption in SBS 0335$-$052 E
• Direct Far-Infrared Metal Abundances (FIRA) I: M101