NGC 2579 and the carbon and oxygen abundance gradients beyond the solar circle

Abstract

We present deep echelle spectrophotometry of the Galactic HII region NGC 2579. The data have been taken with the Very Large Telescope Ultraviolet-Visual Echelle Spectrograph in the 3550--10400 Å range. This object, which has been largely neglected, shows however a rather high surface brightness, a high ionization degree and is located at a galactocentric distance of 12.4 $\pm$ 0.7 kpc. Therefore, NGC 2579 is an excellent probe for studying the behaviour of the gas phase radial abundance gradients in the outer disc of the Milky Way. We derive the physical conditions of the nebula using several emission line-intensity ratios as well as the abundances of several ionic species from the intensity of collisionally excited lines. We also determine the ionic abundances of C${}^{2+}$, O${}^{+}$ and O${}^{2+}$ -- and therefore the total O abundance -- from faint pure recombination lines. The results for NGC 2579 permit to extend our previous determinations of the C, O and C/O gas phase radial gradients of the inner Galactic disc (Esteban etal. 2005) to larger galactocentric distances. We find that the chemical composition of NGC 2579 is consistent with flatten gradients at its galactocentric distance. In addition, we have built a tailored chemical evolution model that reproduces the observed radial abundance gradients of O, C and N and other observational constraints. We find that a levelling out of the star formation efficiency about and beyond the isophotal radius can explain the flattening of chemical gradients observed in the outer Galactic disc.

10 pages, 5 figures. Accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (16)

• Effects of Supernova Feedback on the Formation of Galaxy Disks
• Very low metallicity massive star models: Pre-SN evolution and primary nitrogen production
• Resolving the electron temperature discrepancies in HII Regions and Planetary Nebulae: kappa-distributed electrons
• Keck HIRES Spectroscopy of Extragalactic HII Regions: C and O Abundances from Recombination Lines
• On the abundance discrepancy problem in HII regions
• Elemental Abundance Ratios in Stars of the Outer Galactic Disk. IV. A New Sample of Open Clusters
• The localized chemical pollution in NGC 5253 revisited: Results from deep echelle spectrophotometry
• Faint emission lines in the Galactic H II regions M16, M20 and NGC 3603
• He~I Emission in the Orion Nebula and Implications for Primordial Helium Abundance
• Enrichment of the ISM by metal-rich droplets and the abundance bias in HII regions
• Faint recombination lines in Galactic PNe with [WC] nucleus
• New results on the time variation of the radial abundance gradients from planetary nebulae
• An estimate of the time variation of the abundance gradient from planetary nebulae III. O, S, Ar, and Ne: A comparison of PN samples
• Ionized gas diagnostics from protoplanetary discs in the Orion Nebula and the abundance discrepancy problem
• Multiconfiguration Dirac-Hartree-Fock energy levels and transition probabilities for 3d^5 in Fe IV
• A study of the neglected Galactic HII region NGC 2579 and its companion ESO 370-9

Cited by in corpus (48)

• PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results
• The O3N2 and N2 abundance indicators revisited: improved calibrations based on CALIFA and Te-based literature data
• Understanding Galaxy Evolution through Emission Lines
• A characteristic oxygen abundance gradient in galaxy disks unveiled with CALIFA
• The MOSDEF Survey: Electron Density and Ionization Parameter at $z\sim 2.3$
• Shape of the oxygen abundance profiles in CALIFA face-on spiral galaxies
• Nebular spectroscopy: A guide on H II regions and planetary nebulae
• The shape of oxygen abundance profiles explored with MUSE: evidence for widespread deviations from single gradients
• Carbon and oxygen abundances from recombination lines in low-metallicity star-forming galaxies. Implications for chemical evolution
• Carbon and oxygen in HII regions of the Magellanic Clouds: abundance discrepancy and chemical evolution
• The Galactic radial abundance gradients of C, N, O, Ne, S, Cl and Ar from deep spectra of H II regions
• Carbon and oxygen abundance gradients in NGC300 and M33 from optical recombination lines
• The origin of the high-velocity cloud complex C
• Electron Excitation of High Dipole Moment Molecules Reexamined
• The radial abundance gradient of oxygen towards the Galactic anticentre
• Gradients of chemical abundances in the Milky Way from HII regions: distances derived from Gaia EDR3 parallaxes and temperature inhomogeneities
• 3-D gas-phase elemental abundances across the formation histories of Milky Way-mass galaxies in the FIRE simulations: initial conditions for chemical tagging
• Oxygen abundance distribution in Galactic disc
• Chemical distribution of HII regions towards the Galactic anticentre
• Density biases and temperature relations for DESIRED HII regions
• Analysis of chemical abundances in planetary nebulae with [WC] central stars. II. Chemical abundances and the abundance discrepancy factor
• On the radial abundance gradients of nitrogen and oxygen in the inner Galactic disc
• Carbon, nitrogen and oxygen abundance gradients in M101 and M31
• The Te[N II]-Te[O III] temperature relation in H II regions and the reliability of strong-line methods
• Interaction effects on galaxy pairs with Gemini/GMOS- II: Oxygen abundance gradients
• Bar effect on gas-phase abundance gradients. I. Data sample and chemical abundances
• The time evolution of the Milky Way's oxygen abundance gradient
• The radial abundance gradient of chlorine in the Milky Way
• Review of scientific topics for Millimetron space observatory
• Progressive Red Shifts in the Late-Time Spectra of Type Ia Supernovae
• Dynamics and Morphology of the Milky Way Spiral Arms from the Metallicity Distribution and Radial Mixing
• The Cocoon Nebula and its ionizing star: do stellar and nebular abundances agree?
• Helium abundances and its radial gradient from the spectra of HII regions and ring nebulae of the Milky Way
• The last 5 Gyr of Galactic chemical evolution based on H II region abundances derived from a temperature independent method
• Metallicity Measurements of Gamma-Ray Burst and Supernova Explosion Sites: Lessons from HII regions in M31
• Dispersal timescale of protoplanetary disks in the low-metallicity young cluster Dolidze 25
• Photoionized Herbig-Haro objects in the Orion Nebula through deep high-spectral resolution spectroscopy III: HH514
• LAMOST Medium-Resolution Spectral Survey of Galactic Nebula (LAMOST MRS-N): An overview of Scientific goals and Survey plan
• Open cluster Dolidze 25: Stellar parameters and the metallicity in the Galactic Anticentre
• M101: Spectral Observations of HII Regions and Their Physical Properties
• Gas-phase Fe/O and Fe/N abundances in Star-Forming Regions. Relations between nucleosynthesis, metallicity and dust
• Metallicities in the Outer Regions of Spiral Galaxies
• Deep Narrowband Photometry of the M101 Group: Strong-Line Abundances of 720 HII Regions
• The Trace of the CNO Cycle in the Ring Nebula NGC6888
• Thermal Pressure in Diffuse H2 Gas Measured by Herschel [C II] Emission and FUSE UV H2 Absorption
• Deep high spectral resolution spectroscopy and chemical composition of ionized nebulae
• Metallicity gradients in M31, M33, NGC 300 and the Milky Way using abundances of different elements
• The ADF and the t${}^2$ formalism in H II regions based on the upper mass limit of the IMF for the MW