相关论文: A possible solution to the [alpha/Fe]-sigma proble…
The mean stellar alpha-to-iron abundance ratio ([$\alpha$/Fe]) of a galaxy is an indicator of galactic star formation timescale. It is important for understanding the star formation history of early-type galaxies (ETGs) as their star…
There are strong indications from recent papers (e.g. Worthey et al. 1992) that the abundance ratio of Mg/Fe, and consequently also O/Fe in giant elliptical galaxies is not solar. The line strengths of two Fe lines at 5270 and 5335 A are…
The effects of late gas accretion episodes and subsequent merger-induced starbursts on the photo-chemical evolution of elliptical galaxies are studied and compared to the picture of galaxy formation occurring at high redshift with an unique…
We make use of a semi-analytical model of galaxy formation to investigate the origin of the observed correlation between [a/Fe] abundance ratios and stellar mass in elliptical galaxies. We implement a new galaxy-wide stellar initial mass…
We present a detailed stellar population analysis of 27 massive elliptical galaxies within 4 very rich clusters at redshift z~0.2. We obtained accurate estimates of the mean luminosity-weighted ages and relative abundances of CN, Mg and Fe…
We study the origin of iron and alpha-elements (O, Mg, Si) in clusters of galaxies. In particular, we discuss the [O/Fe] ratio and the iron mass-to-luminosity ratio in the intracluster medium (ICM) and their link to the chemical and…
In this paper we compute new multi-zone photo-chemical evolution models for elliptical galaxies, taking into account detailed nucleosynthetic yields, feedback from supernovae and an initial infall episode. By comparing model predictions…
We compute the chemical evolution of the Galactic bulge in the context of an inside-out model for the formation of the Milky Way. The model contains updated stellar yields from massive stars. The main purpose of the paper is to compare the…
We take advantage of our recently published model for Galaxy Evolution and Assembly (GAEA) to study the origin of the observed correlation between [$\alpha$/Fe] and galaxy stellar mass. In particular, we analyse the role of radio mode AGN…
Using the DR12 public release of APOGEE data, we show that thin and thick disk separate very well in the space defined by [$\alpha$/Fe], [Fe/H] and [C/N]. Thick disk giants have both higher [C/N] and higher [$\alpha$/Fe] than do thin disk…
To address the problem concerning the early formation of stars in massive galaxies, we present the results of a semi-analytic model of galaxy formation which includes a physical description of starbursts triggered by galaxy interactions.…
Recent observations of active galactic nuclei (AGNs) have shown a high Fe~II/Mg~II line-flux ratio in their broad-line regions, nearly independent of redshift up to $z \gtrsim 6$. The high flux ratio requires rapid production of iron in…
The detailed abundance patterns of the stars within galaxies provide a unique window into the history of star formation (SF) at early times. Two widely used `chronometers' include the alpha and iron-peak elements, which are created on short…
We explore the formation of alpha-enhanced and metal-rich stellar populations in the nuclei of luminous ellipticals under the assumption of two extreme galaxy formation scenarios based on hierarchical clustering, namely a fast clumpy…
Using Chandra X-ray observations of young, post-merger elliptical galaxies, we present X-ray characteristics of age-related observational results, by comparing with typical old elliptical galaxies in terms of metal abundances in the hot…
Previous studies of the stellar mean metallicity and [Mg/Fe] values of massive elliptical (E)~galaxies suggest that their stars were formed in a very short timescale which cannot be reconciled with estimates from stellar population…
Different mechanisms for quenching star formation in galaxies are commonly invoked in the literature, but the relative impact of each one at different cosmic epochs is still unknown. In particular, the relation between these processes and…
We present a detailed stellar population analysis of 27 massive elliptical galaxies within 4 very rich clusters at redshift z~0.2: A115, A655, A963 and A2111. Using the new, high-resolution stellar populations models developed in our group,…
The chemical evolution of galaxies is investigated within the framework of the star formation rate (SFR) dependent integrated galactic initial mass function (IGIMF). We study how the global chemical evolution of a galaxy and in particular…
Our current knowledge of star-forming metallicity relies primarily on gas-phase oxygen abundance measurements. This may not allow one to accurately describe differences in stellar evolution and feedback driven by variations in iron…