Related papers: New calibrations for estimating the N/O ratio in H…
Simple relations for deriving the oxygen abundance in HII regions with intensities of the three strong emission lines R_2, R_3, and N_2 (R calibration) or S_2, R_3, and N_2 (S calibration) in their spectra are suggested. A sample of 313…
We suggest an empirical calibration for determination of oxygen and nitrogen abundances and electron temperature in HII regions where the [OII]3727+3729 line (R_2) is not available. The calibration is based on the strong emission lines of…
To calibrate the relationship between Ne3O2 (Ne3O2 = log(\neiii$\lambda3869$/\oii$\lambda3727$)) and oxygen abundances, we present a sample of $\sim$3000 $\hii$ galaxies from the Sloan Digital Sky Survey (SDSS) data release four. They are…
The use of IFS is since recently allowing to measure the emission line fluxes of an increasingly large number of star-forming galaxies both locally and at high redshift. The main goal of this study is to review the most widely used…
We study the relation between nitrogen and oxygen abundances as a function of metallicity for a sample of emission-line objects for which a direct measurement of the metallicity has been possible. This sample is representative of the very…
The HII region oxygen abundance is a key observable for studying chemical properties of galaxies. Deriving oxygen abundances using optical spectra often relies on empirical strong-line calibrations calibrated to the direct method. Existing…
This paper presents a spectroscopic investigation of 11 HII regions in the nearby galaxy NGC 2403. The HII regions are observed with a long-slit spectrograph mounted on the 2.16 m telescope at XingLong station of National Astronomical…
Using a large sample of 38,478 star-forming galaxies selected from the Second Data Release of the Sloan Digital Sky Survey database (SDSS-DR2), we derive analytical calibrations for oxygen abundances from several metallicity-sensitive…
We suggest a new way to establish the relation between the electron temperature t3 within the [OIII] zone and the electron temperature t2 within the [OII] zone in high-metallicity (12+log(O/H) > 8.25) HII regions. The t2 - t3 diagram is…
The Nitrogen-to-Oxygen (N/O) abundance ratio is an important diagnostic of galaxy evolution since the ratio is closely tied to the growth of metallicity and the star formation history in galaxies. Estimates for the N/O ratio are…
We show that in order to minimize the uncertainties in the N and O abundances of low mass, low metallicity (O/H less than or equal to solar/5) emission-line galaxies, it is necessary to employ separate parameterizations for inferring Te[N…
We analysed the optical spectra of HII regions extracted from a sample of 350 galaxies of the CALIFA survey. We calculated total O/H abundances and, for the first time, N/O ratios using the semi-empirical routine HII-CHI-mistry, which,…
We present long slit spectrophotometry of two HII regions: TOL2146-391 and TOL0357-3915. We performed a detailed analysis that involves abundance determinations relaxing the assumption of homogeneous temperature. The temperature…
Based on O II recombination lines we present a new calibration (called O II[RL]) of Pagel's O23 indicator to determine the O/H abundance ratio in extragalactic H II regions and emission line galaxies. The O II(RL) calibration produces O/H…
We present long slit optical spectroscopy of 67 HII regions in 21 dwarf irregular galaxies to investigate the enrichment of oxygen, nitrogen, neon, sulfur, and argon in low mass galaxies. Oxygen abundances are obtained via direct detection…
We present spectra obtained with the 10.4 m Gran Telescopio Canarias telescope of 13 Galactic HII regions, most of them of very low ionisation degree. The objects are located along the Galactic disc, with R_G from 5.7 to 16.1 kpc. We…
The problem of the line intensities -- oxygen abundance calibration has been considered. We confirm the idea of McGaugh (1991) that the strong oxygen lines ([OII] 3727, 3729 and [OIII] 4959, 5007) contain the necessary information for…
We investigate two chemical abundance calibrations for the narrow-line-region (NLR) of active galaxies in terms of three easily observable optical emission-line ratios, namely, [OIII]$\lambda\lambda$4959,5007/H$\beta$,…
We determine the gas-phase oxygen abundance for a sample of 695 galaxies and H II regions with reliable detections of [O III]4363, using the temperature-sensitive Te method. Our aims are to estimate the validity of empirical methods such as…
We present the results of nitrogen and oxygen abundance measurements for 185 HII regions spanning a range of radius in 13 spiral galaxies. As expected, the nitrogen-to-oxygen ratio increases linearly with the oxygen abundance for high…