Related papers: Dissipation and Extra Light in Galactic Nuclei: II…
Results from IRAS and recent X-ray and optical surveys are reviewed to discuss the properties and nature of the interstellar medium in elliptical galaxies. As to the dust component, there is a strong contrast with the situation among spiral…
Given its velocity dispersion, the early-type galaxy NGC 1600 has an unusually massive ($M_\bullet = 1.7 \times 10^{10} M_\odot$) central supermassive black hole (SMBH), surrounded by a large core ($r_\mathrm{b} = 0.7$ kpc) with a…
The scenario of galaxy formation is believed to follow a structure that builds up from the bottom, with large galaxies being formed by several merging episodes of smaller ones. In this scenario a number of galaxies can be expected to be…
In order to investigate the formation mechanisms of the rare compact elliptical galaxies (cE) we have compiled a sample of 25 cEs with good SDSS spectra, covering a range of stellar masses, sizes and environments. They have been visually…
We analyze the behavior of the outer envelope in a massive star during and after the collapse of its iron core into a protoneutron star (PNS) in terms of the equations of one-dimensional spherically symmetric ideal hydrodynamics. The…
This is the summary chapter of a review book on galaxy bulges. Bulge properties and formation histories are more varied than those of ellipticals. I emphasize two advances: 1 - "Classical bulges" are observationally indistinguishable from…
We used the Advanced Camera for Surveys on board the Hubble Space Telescope to obtain high resolution i-band images of the centers of 23 single galaxies, which were selected because they have SDSS velocity dispersions larger than 350 km/s.…
We study the distribution of orbital eccentricities of stars in thick disks generated by the heating of a pre-existing thin stellar disk through a minor merger (mass ratio 1:10), using N-body/SPH numerical simulations of interactions that…
We present the results of N-body simulations of the accretion of high-density dwarf galaxies by low-density giant galaxies. Both galaxies contain power-law central density cusps and point masses representing supermassive black holes; the…
We study the stellar and dust properties of a well-defined sample of local elliptical galaxies to investigate the relationship between host galaxy properties and nuclear activity. We select a complete sample of 45 ellipticals from the…
In order to investigate the nature and origin of dust in elliptical galaxies, a method for the dust mass evaluation, which accounts for the dust temperature distribution, is here presented and discussed. The derived dust masses turn out to…
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 show, using the N-body code GADGET-2, that stellar scattering by massive clumps can produce exponential discs, and the effectiveness of the process depends on the mass of scattering centres, as well as the stability of the galactic disc.…
Context. The cusp-core discrepancy is one of the major problems in astrophysics. It results from comparing the observed mass distribution of galaxies with the predictions of Cold Dark Matter simulations. The latter predict a cuspy density…
Sersic parameters characterising the density profiles of remnants formed in collision-less disc galaxy mergers are obtained; no bulge is included in our simulations. For the luminous component we find that the Sersic index is n ~ (1.5,5.3)…
We present results from a pilot HST ACS deep imaging study in broad-band V of five low-redshift QSO host galaxies classified in the literature as ellipticals. The aim of our study is to determine whether these early-type hosts formed at…
We have examined the effect of slow growth of a central black hole on spherical galaxies that obey S\'ersic or $R^{1/m}$ surface-brightness profiles. During such growth the actions of each stellar orbit are conserved, which allows us to…
We present numerical investigations into the formation of massive stars from centrally condensed turbulent cores. The results of five hydrodynamical simulations are described, following the collapse of the core, fragmentation and the…
The relaxed distribution of stars around a massive black hole is known to follow a cusp profile $\rho(r)\propto r^{-\alpha}$ with characteristic slope $\alpha=7/4$. This follows from energy conservation and a scattering rate as given by two…
The mid-infrared (10-20 um) luminosity of elliptical galaxies is dominated by the integrated emission from circumstellar dust in red giant stars. As a single stellar population evolves, the rate of dusty mass loss from red giant stars…