Mon. Not. R. Astron. Soc., 496, 1051-1076 (2020/August-1)
The Galactic radial abundance gradients of C, N, O, Ne, S, Cl, and Ar from deep spectra of H II regions.
ARELLANO-CORDOVA K.Z., ESTEBAN C., GARCIA-ROJAS J. and MENDEZ-DELGADO J.E.
Abstract (from CDS):
We present a reassessment of the radial abundance gradients of C, N, O, Ne, S, Cl, and Ar in the Milky Way using deep spectra of 33 H II regions gathered from the literature, covering Galactocentric distances from 6 to 17 kpc. The distances of the objects have been revised using Gaia parallaxes. We recalculate the physical conditions and ionic abundances in an homogeneous way using updated atomic data. All the objects have direct determination of the electron temperature, permitting to derive their precise ionic abundances. We analyse and compare different ICF schemes for each element in order to obtain the most confident total abundances. Due to the revised distances, our results do not support previous claims about a possible flattening of the O/H gradient in the inner Galactic disc. We find that the Galactic N/O gradient is rather flat, in contrast to what has been found in other spiral galaxies. The slope of the gradients of some elements is sensitive to the ICF scheme used, especially in the case of Ne. The dispersion around the fit for the gradients of C, N, O, S, Cl, and Ar is of the order of the typical uncertainties in the determination of the abundances, implying the absence of significant inhomogeneities in the chemical composition of the ionized gas phase of the ISM. We find flat gradients of log(S/O) and log(Cl/O) and very shallow or flat ones for log(Ne/O) and log(Ar/O), consistent with a lockstep evolution of Ne, S, Cl, and Ar with respect to O.
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
ISM: abundances - H ii regions - Galaxy: abundances - Galaxy: disc
Status at CDS
Large table(s) will be appraised for possible ingestion in VizieR.
View the reference in ADS
To bookmark this query, right click on this link: simbad:2020MNRAS.496.1051A and select 'bookmark this link' or equivalent in the popup menu