Related papers: Faint galaxies in semi--analytic models: how robus…
We present models predicting the magnitude, redshift, and color distributions of field galaxies. We explore whether a fading starburst scenario can account for the observations of faint blue galaxies. We marginally rule out a starburst…
We derive the luminosity and multiplicity functions of superclusters compiled for the 2dF Galaxy Redshift Survey, the Sloan Digital Sky Survey (Data Release 4), and for three samples of simulated superclusters. We find for all supercluster…
High-redshift galaxy clusters allow us to examine galaxy formation in extreme environments. Here we compile data for 15 $z>1$ galaxy clusters to test the predictions from a state-of-the-art semi-analytical model of galaxy formation. The…
Next generation large sky surveys will observe up to billions of galaxies for which basic structural parameters are needed to study their evolution. This is a challenging task that, for ground-based observations, is complicated by seeing…
We present results from the semi-analytic model of galaxy formation SAG applied on the MultiDark simulation MDPL2. SAG features an updated supernova (SN) feedback scheme and a robust modelling of the environmental effects on satellite…
Luminosity Functions have been obtained for very faint dwarf galaxies in the cores of four rich clusters of galaxies (Abell 2052, 2107, 2199 and 2666). It is found that the luminosity function of dwarf galaxies rises very steeply in these…
We develop a new realistic prescription for modeling the stellar feedback, which minimizes any ad hoc assumptions about sub-grid physics. We start with developing high resolution models of the ISM and formulate the conditions required for…
We investigate the role of stellar mass in shaping the intrinsic thickness of faint systems by determining the probability distribution of apparent axis ratios for two different samples that probe the faint end of the galaxy luminosity…
We fit the recently updated UV luminosity functions (LF) of high-$z$ ($1.5\le z\le8.0$) galaxies using our semi-analytical models of galaxy formation that take into account various feedback processes. In order to reproduce the overall…
Recent analyses show that $\Lambda$CDM-based models optimised to reproduce the clustering of massive galaxies overestimate their gravitational lensing by about 30\%, the so-called lensing is low problem. Using a state-of-the-art…
Semi-analytic models (SAMs) are currently one of the primary tools with which to model statistically significant ensembles of galaxies. The underlying physical prescriptions inherent to each SAM are, in many cases, different from one…
We measure the redshift-dependent luminosity function and the comoving radial density of galaxies in the Sloan Digital Sky Survey Data Release 1 (SDSS DR1). Both measurements indicate that the apparent number density of bright galaxies…
Modifications of the equations of general relativity at large distances offer one possibility to explain the observed properties of our Universe without invoking a cosmological constant. Numerous proposals for such modified gravity…
Galaxies in the Las Campanas Redshift Survey are classified according to their spectra, and the resulting spectral types are analyzed to determine if local environment affects their properties. We find that the luminosity function of…
We have worked out simple analytical formulae that accurately approximate the relationship between the position of the source with respect to the lens center and the amplification of the images, hence the lens cross section, for realistic…
We use semi-analytic models of galaxy formation combined with high resolution N-body simulations to make predictions for galaxy-dark matter correlations and apply them to galaxy-galaxy lensing. We analyze cross-correlation spectra between…
We measure the luminosity function of QSOs in the redshift range 3.5 < z < 5.2 for the absolute magnitude interval -21 < M_{145} < -28. Suitable criteria are defined to select faint QSOs in the GOODS fields, checking their effectiveness and…
Star-forming dwarfs are studied to elucidate the physical underpinnings of their fundamental plane. It is confirmed that residuals in the Tully-Fisher relation are correlated with surface brightness, but that even after accommodating the…
The standard cosmological model based on cold dark matter (CDM) predicts a large number of subhalos for each galaxy-size halo. It is well known that matching the subhalos to the observed properties of luminous satellites of galaxies in the…
Dwarf, irregular and infrared-luminous starburst galaxies are all known to have "steep" luminosity functions with faint-end behavior roughly phi(L)-propto- L^(-1.8). This form is exactly what is expected if the luminosities of these objects…