Related papers: On the origin of nitrogen
We derive the nitrogen and oxygen abundances in the Narrow Line Regions (NLRs) of a sample of 38 local ($z \: < \: 0.4$) Seyfert~2 nuclei. For that, we consider narrow optical emission line intensities and direct estimates of the electron…
Galactic and extragalactic abundance studies of H II regions, planetary nebulae, and supernova remnants are compiled and their implications briefly reviewed. Galaxy global metallicity appears to be related directly to total mass and…
The abundances of iron and oxygen are homogeneously determined in a sample of 523 nearby (d<150 pc) FGK disk and halo stars with metallicities in the range -1.5<[Fe/H]<0.5. The oxygen abundances were inferred from a restricted non-LTE…
(Abridged) We reassess the alpha-element abundance ratios (Ne/O, S/O, Ar/O) with respect to metallicity in ~1000 spectra of Galactic and extragalactic HII regions and star-forming galaxies (SFGs) of the local Universe. Using the DEep…
By comparing observed abundance gradients with those predicted by a chemodynamical model of the Galaxy the following results are obtained: there is a defficiency of O/H poor PNe in the solar vicinity which implies that only a fraction of…
The low-luminosity dwarf irregular galaxies are considered. The oxygen abundances in HII regions of dwarf irregular galaxies were recalculated from published spectra through the recently suggested P - method. It has been found that the…
We present a detailed spectroscopic analysis of nitrogen abundances in 91 solar-type stars, 66 with and 25 without known planetary mass companions. All comparison sample stars and 28 planet hosts were analysed by spectral synthesis of the…
Recent observations of GN-z11 with JWST/NIRSpec revealed numerous oxygen, carbon, nitrogen, and helium emission lines at $z=10.6$. Using the measured line fluxes, we derive abundance ratios of individual elements within the interstellar…
Context. Growing evidence is revealing the crucial role of binarity in massive star evolution. This affects evolution models and demands a refinement of the available observational constraints. Aims. To investigate the possible evolutionary…
Our knowledge of galactic chemical evolution is currently limited to observations of Milky Way stars and H II regions of nearby galaxies. Damped Lyman~$\alpha$ systems offer a new approach for tracking the evolution of normal galaxies from…
We have observed emission lines of [S IV] 10.51, H(7-6) 12.37, [Ne II] 12.81, [Ne III] 15.56, and [S III] 18.71 um in a number of extragalactic H II regions with the Spitzer Space Telescope. A previous paper presented our data and analysis…
The results of the N/O abundance determination in a sample of low-metallicity blue compact dwarf (BCD) galaxies based on new spectroscopic observations with large telescopes (Keck, VLT, MMT, 4m KPNO) are presented. We show that the N/O…
The new era of galaxy evolution studies hearkened in by JWST has led to the discovery of z > 5 galaxies exhibiting excess nitrogen with log(N/O)~1 dex or more than expected from log(N/O) vs 12+log(O/H) trends in the local Universe. A…
The composition of giant planets is imprinted by their migration history and the compositional structure of their hosting disks. Studies in recent literature investigate how the abundances of C and O can constrain the formation pathways of…
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…
This study focuses on some of the most metal-poor damped Lyman alpha absorbers known in the spectra of high redshift QSOs, using new and archival observations obtained with UV-sensitive echelle spectrographs on the Keck and VLT telescopes.…
We present chemical abundance ratios of 8 nitrogen-rich ([N/O]$>0.3$) galaxies at $z\sim 6-12$ identified by the first 4 years of the JWST observations, and compare these ratios with chemical evolution models. We reanalyze the JWST/NIRSpec…
Recent JWST observations have revealed a growing population of galaxies at $z>4$ with elevated nitrogen-to-oxygen ratios. These "N/O-enhanced" galaxies (NOEGs) exhibit near- to super-solar N/O at sub-solar O/H, clearly deviating from the…
Because of their low gravitational energies dwarf galaxies are greatly exposed to energetical influences by the interstellar medium, like e.g.\ stellar radiation, winds or explosions, or by their environment. While the metallicity depletion…
The cosmological origin of carbon, the fourth most abundant element in the Universe, is not well known and matter of heavy debate. We investigate the behavior of C/O to O/H in order to constrain the production mechanism of carbon. We…