ﻻ يوجد ملخص باللغة العربية
To show that the bulk of the star formation and the galaxy assembly should occur simultaneously in order to reproduce at the same time the downsizing and the chemical properties of present-day massive spheroids within one effective radius.By means of chemical evolution models we create galactic building blocks of several masses and different chemical properties. We then construct a sample of possible merger histories going from a multiple minor merger scenario to a single major merger event aimed at reproducing a single massive elliptical galaxy. We compare our results against the mass-[Mg/Fe] and the mass-metallicity relations. We found that a series of multiple dry-mergers (no star formation in connection with the merger) involving building-blocks which have been created ad hoc in order to satisfy the [Mg/Fe]-mass relation cannot fit the mass-metallicity relation and viceversa. A major dry merger, instead, does not worsen the agreement with observation if it happens between galaxies which already obey to both the mass- or sigma-[Mg/Fe] and the mass-(sigma-) metallicity relations. However, this process alone cannot explain the physical reasons for these trends. Dry mergers alone cannot be the way to reconcile the need of a more efficient star formation in the most massive galaxies with the late time assembly suggested in the hierarchical paradigm in order to recover the galaxy downsizing.
We use a cosmological numerical simulation to study the tidal features produced by a minor merger with an elliptical galaxy. We find that the simulated tidal features are quantitatively similar to the red tidal features, i.e., dry tidal features, rec
Here we present a possible solution to the apparent discrepancy between the observed properties of LMC bubbles and the standard, constant density bubble model. A two-dimensional model of a wind-driven bubble expanding from a flattened giant molecular
Using data from the Spitzer Space Telescope, we analyze the mid-infrared (3-70 micron) spectral energy distributions of dry merger candidates in the Bootes field of the NOAO Deep Wide-Field Survey. These candidates were selected by previous authors t
Mergers between red galaxies are observed to be common in the nearby Universe, and are thought to be the dominant mechanism by which massive galaxies grow their mass at late times. These ``dry mergers can be readily identified in very deep ground bas
We study how well we can reconstruct the 2-point clustering of galaxies on linear scales, as a function of mass and luminosity, using the halo occupation distribution (HOD) in several semi-analytical models (SAMs) of galaxy formation from the Millenn