ﻻ يوجد ملخص باللغة العربية
We present a new class of hydrodynamical models for the formation of bulges (either massive elliptical galaxies or classical bulges in spirals) in which we implement detailed prescriptions for the chemical evolution of H, He, O and Fe. Our results hint toward an outside-in formation in the context of the supernovae-driven wind scenario. The build-up of the chemical properties of the stellar populations inhabiting the galactic core is very fast. Therefore we predict a non significant evolution of both the mass-metallicity and the mass-[alpha/Fe] relations after the first 0.5 - 1 Gyr. In this framework we explain how the observed slopes, either positive or negative, in the radial gradient of the mean stellar [alpha/Fe], and their apparent lack of any correlation with all the other observables, can arise as a consequence of the interplay between star formation and metal-enhanced internal gas flows.
I review the observational characteristics of intermediate-to-high redshift star forming galaxies, including their star formation rates, dust extinctions, ISM kinematics, and chemical compositions. I present evidence that the mean rate of metal enric
We present new deep optical spectra of 9 high-z radio galaxies (HzRGs) at z > 2.7 obtained with FORS2 on VLT. These rest-frame ultraviolet spectra are used to infer the metallicity of the narrow-line regions (NLRs) in order to investigate the chemica
This chapter summarizes our current understanding of the stellar population properties of bulges and outlines important future research directions.
Using a sample of 57 VLT FORS spectra in the redshift range 1.37<z<3.40 (selected mainly from the FORS Deep Field survey) and a comparison sample with 36 IUE spectra of local (z ~ 0) starburst galaxies we derive CIV and SiIV equivalent width values a
Many galaxies at high redshift have peculiar morphologies dominated by 10^8-10^9 Mo kpc-sized clumps. Using numerical simulations, we show that these clump clusters can result from fragmentation in gravitationally unstable primordial disks. They appe