相关论文: The Iron Discrepancy in Elliptical Galaxies after …
Dwarf irregular and blue compact galaxies are very interesting objects since they are relatively simple and unevolved. We present new models for the chemical evolution of these galaxies by assuming different regimes of star formation…
The uniformity of the intra-cluster medium (ICM) enrichment level in the outskirts of nearby galaxy clusters suggests that chemical elements were deposited and widely spread into the intergalactic medium before the cluster formation. This…
We analyze a sample of 3,944 low-resolution (R ~ 2000) optical spectra from the Sloan Digital Sky Survey (SDSS), focusing on stars with effective temperatures 5800 < Teff < 6300 K, and distances from the Milky Way plane in excess of 5 kpc,…
We investigate the history of galactic feedback and chemical enrichment within a sample of 15 X-ray bright groups of galaxies, on the basis of the inferred Fe and Si distributions in the hot gas and the associated metal masses produced by…
The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the…
The comparison of chemical abundances in the neutral gas of galaxies to photospheric abundances of old and young stars, ionized gas abundances, and abundances in galactic halos can trace the chemical enrichment of the universe through…
We study the hydrodynamical evolution of galactic winds in disky dwarf galaxies moving through an intergalactic medium. In agreement with previous investigations,we find that when the ram pressure stripping does not disrupt the ISM, it…
According to observations and numerical simulations, the Milky Way could exhibit several spiral arm modes with multiple pattern speeds, wherein the slower patterns are located at larger Galactocentric distances. Our aim is to quantify the…
Recent evidence based independently on spectral line strengths and dynamical modelling point towards a non-universal stellar Initial Mass Function (IMF), probably implying an excess of low-mass stars in elliptical galaxies with a high…
In this paper we analyze the diffuse X-ray coronae surrounding the elliptical galaxy NGC5846, combining measurements from two observatories, ROSAT and ASCA. We map the gas temperature distribution and find a central cool region within an…
The chemical enrichment in the interstellar medium (ISM) of galaxies is regulated by several physical processes: stellar evolution, grain formation and destruction, galactic inflows and outflows. Understanding such processes is essential to…
We have analyzed 17 early-type galaxies, 13 ellipticals and 4 S0's, observed with Suzaku, and investigated metal abundances (O, Mg, Si, and Fe) and abundance ratios (O/Fe, Mg/Fe, and Si/Fe) in the interstellar medium (ISM). The emission…
We study the nature of Damped Lyman -Alpha systems (DLAs) by means of a comparison between observed abundances and models of chemical evolution of galaxies of different morphological type. In particular, we compare for the first time the…
We use our new stellar population models, which include effects from variable element abundance ratios, to model the Ca4227 absorption line indices of early-type galaxies (Trager et al.), and to derive calcium element abundances. We find…
The interstellar medium (ISM) in starburst galaxies contains plenty of chemical elements synthesised by core-collapse supernova explosions. By measuring the abundances of these metals, we can study the chemical enrichment within galaxies…
We have examined the metal enrichment of the intergalactic medium (IGM) based on a galactic wind model. A galactic wind driven by supernovae brings metallic gas to the IGM but not so far beyond the gravitational potential. The expanding…
We introduce a stochastic halo formation model to compute the early chemical enrichment of the interstellar medium (ISM) of the halo. Contrary to 1-zone chemical evolution models, we are able to resolve local inhomogeneities in the ISM…
Resolved metallicity studies of local disk galaxies have revealed that their interstellar media (ISMs) are far from chemically homogeneous, displaying significant ($\sim 0.05$ dex) variations in the metallicity on characteristic scales of a…
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…
(Abridged) We present an implementation of stellar evolution and chemical feedback for smoothed particle hydrodynamics (SPH) simulations. We consider the timed release of individual elements by both massive (Type II supernovae and stellar…