Revisiting the abundance gradient in the maser host galaxy NGC 4258

Abstract

New spectroscopic observations of 36 HII regions in NGC 4258 obtained with the Gemini telescope are combined with existing data from the literature to measure the radial oxygen abundance gradient in this galaxy. The [OIII]4363 auroral line was detected in four of the outermost targets (17 to 22 kpc from the galaxy center), allowing a determination of the electron temperature Te of the ionized gas. From the use of different calibrations of the R23 abundance indicator an oxygen abundance gradient of approximately -0.012 +/- 0.002 dex/kpc is derived. Such a shallow gradient, combined with the difference in the distance moduli measured from the Cepheid Period-Luminosity relation by Macri et al. between two distinct fields in NGC 4258, would yield an unrealistically strong effect of metallicity on the Cepheid distances. This strengthens the suggestion that systematic biases might affect the Cepheid distance of the outer field. Evidence for a similar effect in the differential study of M33 by Scowcroft et al. is presented. A revision of the transformation between strong-line and Te-based abundances in Cepheid-host galaxies is discussed. In the Te abundance scale, the oxygen abundance of the inner field of NGC 4258 is found to be comparable with the LMC value.

Accepted for publication in the Astrophysical Journal

References in corpus (25)

• A new Cepheid distance to the maser-host galaxy NGC 4258 and its implications for the Hubble Constant
• Extragalactic chemical abundances: do HII regions and young stars tell the same story? The case of the spiral galaxy NGC 300
• The influence of chemical composition on the properties of Cepheid stars. II-The iron content
• A cosmic abundance standard: chemical homogeneity of the solar neighbourhood and the ISM dust-phase composition
• Cepheid Parallaxes and the Hubble Constant
• Cepheid Distances to SNe Ia Host Galaxies based on a Revised Photometric Zero-Point of the HST-WFPC2 and New P-L Relations and Metallicity Corrections
• Keck HIRES Spectroscopy of Extragalactic HII Regions: C and O Abundances from Recombination Lines
• The M33 Metallicity Project: Resolving the Abundance Gradient Discrepancies in M33
• Quantitative Spectroscopy of 24 A supergiants in the Sculptor galaxy NGC 300: Flux weighted gravity luminosity relationship, metallicity and metallicity gradient
• The localized chemical pollution in NGC 5253 revisited: Results from deep echelle spectrophotometry
• The oxygen abundance in the inner HII regions of M101. Implications for the calibration of strong-line metallicity indicators
• The metallicity gradient of M 33: chemical abundances of HII regions
• Cepheid Calibrations of Modern Type Ia Supernovae:Implications for the Hubble Constant
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• Properties of the ionized gas in HH202. II: Results from echelle spectrophotometry with UVES
• The Araucaria Project. VLT spectra of blue supergiants in WLM: classification and first abundances
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• Toward a New Distance to the Active Galaxy NGC 4258: II. Centripetal Accelerations and Investigation of Spiral Structure
• Comparison of Distances from RR Lyrae Stars, the Tip of the Red-Giant Branch and Classical Cepheids
• Cepheids in external galaxies. I. The maser-host galaxy NGC 4258 and the metallicity dependence of P-L and P-W relations
• The Distances to Open Clusters from Main-Sequence Fitting. IV. Galactic Cepheids, the LMC, and the Local Distance Scale
• Classical Cepheid Pulsation Models. XI. Effects of convection and chemical composition on the Period-Luminosity and Period-Wesenheit relations
• Metallicity-corrected Tip of the Red Giant Branch Distance to NGC 4258
• The chemical composition of planetary nebulae and HII regions in NGC 3109
• The ACS Nearby Galaxy Survey Treasury III: Cepheids in the Outer Disk of M81

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