Related papers: On the origin of nitrogen
Anomalously high nitrogen-to-oxygen abundance ratios [N/O] are observed in globular clusters (GCs), among the field stars of the Milky Way (MW), and even in the gas in a $z\approx 11$ galaxy. Using data from the APOGEE Data Release 17 and…
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…
CNO abundances in galaxies bear on issues of galactic evolution as well as stellar evolution and nucleosynthesis. Knowledge about them in dwarf and spiral galaxies depends mainly on emission lines from H II regions, with information from…
We employ analytical and numerical chemical evolution models to study observed trends in abundance ratios involving carbon, nitrogen, and oxygen. Several sets of published stellar yields for both intermediate-mass and massive stars are…
The abundance ratio N/O is a useful tool to study the interplay of galactic processes, e.g. star formation efficiency, time-scale of infall and outflow loading factor We aim to trace log(N/O) versus [Fe/H] in the Milky Way and to compare it…
We performed a compilation of more than 1000 published spectra of HII regions in spiral galaxies. The oxygen and nitrogen abundances in each HII region were recomputed in a homogeneous way, using the P-method. The radial distributions of…
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…
The abundance of nitrogen in the interstellar medium is a powerful probe of star for- mation processes over cosmological timescales. Since nitrogen can be produced both in massive and intermediate-mass stars with metallicity-dependent…
We have obtained deep spectra of 26 planetary nebulae (PNe) and 9 compact HII regions in the nearby spiral galaxy NGC 300, and analyzed them together with those of the giant HII regions previously observed. We have determined the physical…
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…
We study the evolution of nitrogen in the Galactic halo, thick disc, thin disc and bulge by comparing detailed chemical evolution models with recent observations. The models used in this work have already been constrained to explain the…
We propose an evolutionary scenario by successive bursts of star formation to reproduce the chemical properties of massive nearby Starburst Nucleus Galaxies (SBNGs). The N/O abundance ratios in SBNGs are 0.2 dex higher than in normal HII…
The oxygen and nitrogen abundances in the HII regions of the nine Virgo spirals of the sample from Skillman et al (1996) and in nine field spiral galaxies are re-determined with the recently suggested P - method. We confirm that there is an…
We present deep spectrophotometry of 18 HII regions in the nearby massive spiral galaxies M101 and M31. We have obtained direct determinations of electron temperature in all the nebulae. We detect the CII 4267 line in several HII regions,…
We carefully analyze how the abundance of Nitrogen over Oxygen evolves when dependent on metallicity stellar yields with a primary component of N proceeding from AGBs stars are used. We show the results obtained with a chemical evolution…
Spectroscopic observations of 63 HII regions in six spiral galaxies (NGC 628, NGC 783, NGC 2336, NGC 6217, NGC 7331, and NGC 7678) were carried out with the 6-meter telescope (BTA) of Russian Special Astrophysical Observatory with the…
We present nitrogen abundance measurements based on the low-ionisation [NII]6583 emission line for 588 galaxies between 1.5<z<7.0 from the JWST Advanced Deep Extragalactic Survey (JADES). We detect the temperature-sensitive [OIII]4363…
Isotopic ratios are keys to understanding the origin and early evolution of the solar system in the context of Galactic nucleosynthesis. The large range of measured $^{14}$N/$^{15}$N isotopic ratios in the solar system reflects distinct…
We investigate the chemical evolution of N/O using a sample of 45 local star-forming galaxies (SFGs) from the CLASSY survey. This sample spans a wide range of galaxy properties, with robust determinations of nitrogen and oxygen abundances…
We present a comprehensive analysis of the nitrogen-to-oxygen (N/O) abundance ratio in a sample of ~ 660 star-forming galaxies at redshift z ~ 1-6, with a median redshift of z = 3.0, using deep JWST/NIRSpec spectroscopy. Leveraging…