相关论文: Connecting JWST discovered N/O-enhanced galaxies t…
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…
With the launch of the JWST, we will obtain more precise data for exoplanets than ever before. However, this data can only inform and revolutionize our understanding of exoplanets when placed in the larger context of planet-star formation.…
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…
Open clusters are key tools to study the spatial distribution of abundances in the disk and their evolution with time. Using the first release of stellar parameters and abundances of the Gaia-ESO Survey, we analyse the chemical properties…
Carbon, nitrogen, and oxygen (CNO) are key elements in stellar formation and evolution, and their abundances should also have a significant impact on planetary formation and evolution. We present a detailed spectroscopic analysis of 74…
We present an analysis of metallicities and chemical abundances at $3<z<12$ in the THESAN-ZOOM simulations. We find that smoothly curved gas-phase and stellar mass-metallicity relations (MZR) are already in place at $z\approx12$ and evolve…
This paper presents the first results from a model for chemical evolution that can be applied to N-body cosmological simulations and quantitatively compared to measured stellar abundances from large astronomical surveys. This model…
We present JWST/NIRSpec PRISM follow-up of candidate galaxies at z=9-11 selected from deep JWST/NIRCam photometry in GLASS-JWST Early Release Science data. We spectroscopically confirm six sources with secure redshifts at z = 9.52-10.43,…
We present estimates of CN and Mg overabundances with respect to Fe for early-type galaxies in 8 clusters over a range of richness and morphology. Spectra were taken from the Sloan Digital Sky Survey (SDSS) DR1, and from WHT and CAHA…
Chemical evolution models for the Galactic disk under an inside-out formation scenario are presented for seven sets of stellar yields, all of them metal dependent. In particular, the effects of yields from massive and…
This Letter presents a new, remarkably simple diagnostic specifically designed to derive chemical abundances for high redshift galaxies. It uses only the H \alpha, [N II] and [S II] emission lines, which can usually be observed in a single…
In four globular clusters (GCs) a non negligible fraction of stars can be interpreted only as a very helium rich population. The evidence comes from the presence of a "blue" main sequence in $\omega$ Cen and NGC 2808, and from the the very…
Our work focuses on the understanding of the origin of CNO-anomalies, which have been detected in several Galactic globular clusters (GCs). This study is based on a homogeneous data set of hundreds of medium resolution spectra of stars in…
The validity of oxygen and nitrogen abundances derived from the global emission-line spectra of galaxies via the P-method has been investigated using a collection of published spectra of individual HII regions in irregular and spiral…
The determination of chemical abundances in star-forming galaxies and the study of their evolution on cosmological timescales are powerful tools for understanding galaxy formation and evolution. This contribution presents the latest results…
Globular clusters (GCs) are the oldest stellar systems in the Milky Way. Long time considered as simple stellar populations, nowadays we recognize their complex star formation history through precise abundance analysis of a variety of…
Context. Carbon, nitrogen, and oxygen are the most abundant elements throughout the universe, after hydrogen and helium. Studying these elements in low-metallicity stars can provide crucial information on the chemical composition in the…
(Abridged) Using luminosities and structural parameters of globular clusters (GCs) in the nuclear regions (nGCs) of low-mass dwarf galaxies from HST/ACS imaging we derive the present-day escape velocities (v_esc) of stellar ejecta to reach…
Aim of this work is to determine C, N, and O abundances in stars of Galactic open clusters of the Gaia-ESO survey and to compare the observed abundances with those predicted by current stellar and Galactic evolution models. In this pilot…
Context. Low- and intermediate-mass giants undergo a complex chemical evolution that has yet to be observationally probed. The influence of core helium flash on the chemical composition of stellar atmospheres has been an open question since…