Related papers: The Evolution and Luminosity Function of Quasars f…
Recent studies have derived quasar luminosity functions (QLFs) at various redshifts. However, the faint side of the QLF at high redshifts is still too uncertain. An accurate estimate of the survey completeness is essential to derive an…
We investigate the implications of the intergalactic opacity for the evolution of the cosmic UV luminosity density and its sources. Our main constraint is our measurement of the Lya forest opacity at redshifts 2<z<4.2 from 86…
In this paper we examine magnitudes of quasars as a function of redshift in different frequency ranges (u,g,r,i,z). We show that on the smoothed curves mag(Z) in frequency ranges u,g,r there are characteristic features both similar for all…
We present the galaxy optical luminosity function for the redshift range 0.05<z<0.75 from the AGN and Galaxy Evolution Survey (AGES), a spectroscopic survey of 7.6 sq. deg. in the Bootes field of the NOAO Deep Wide-Field Survey. Our…
Significant clustering around the rarest luminous quasars is a feature predicted by dark matter theory combined with number density matching arguments. However, this expectation is not reflected by observations of quasars residing in a…
Emission line galaxies are one of the main tracers of the large-scale structure to be targeted by the next-generation dark energy surveys. To provide a better understanding of the properties and statistics of these galaxies, we have…
We use the ROSAT All Sky Survey (RASS) to study the soft X-ray properties of a homogeneous sample of 46,420 quasars selected from the third data release of the Sloan Digital Sky Survey (SDSS). Optical luminosities, both at rest-frame…
We study the redshift evolution of the quasar UV Luminosity Function (LF) for 0.5 < z < 6.5, by collecting the most up to date observational data and, in particular, the recently discovered population of faint AGNs. We fit the QSO LF using…
In a wide class of cosmological models, a positive cosmological constant drives cosmological evolution toward an asymptotically de Sitter phase. Here we connect this behavior to the increase of entropy over time, based on the idea that de…
We present a new measurement of the evolving galaxy far-IR luminosity function (LF) extending out to redshifts z~5, with resulting implications for the level of dust-obscured star-formation density in the young Universe. To achieve this we…
This study explores the impact of cosmic curvature on structure formation through general relativistic first-order perturbation theory. We analyze continuity and Euler equations, incorporating cosmic curvature into Einstein equations.…
We constructed a model of infrared and sub-mm (hereafter IR) galaxy number count and estimated history of the IR luminosity density. We treat the evolutionary change of galaxy luminosities as a stepwise nonparametric form, in order to…
The distribution function of quasars with respect to apparent brightness is given, found under the assumption that quasars are, at least partially, the gravitationally enhanced images of the active nuclei of distant galaxies. A Schechter…
An accelerated expansion phase is being experienced by the universe due to the presence of an unknown energy component known as dark energy (DE). To find out the cosmic evolution scientists ever tried to modify Einstein's gravitational…
We present a statistical analysis of the final lens sample from the Sloan Digital Sky Survey Quasar Lens Search (SQLS). The number distribution of a complete subsample of 19 lensed quasars selected from 50,836 source quasars is compared…
We have measured the 3.6 micron luminosity evolution of about 1000 galaxies in 32 clusters at 0.2<z<1.25, without any a priori assumption about luminosity evolution, i.e. in a logically rigorous way. We find that the luminosity of our…
I review a technique for interpreting faint galaxy data which traces the evolution with cosmic time of the galaxy luminosity density, as determined from several deep spectroscopic samples and the HDF. The method relies on the rest frame UV…
We describe a numerical algorithm which simulates the propagation of light in inhomogeneous universes, using the multiple lens-plane method. The deformation and deflection of light beams as they interact with each lens plane are computed…
We present a measurement of the evolution of the stellar mass function in four redshift bins at 0.4 < z < 1.2 using a sample of more than 5000 K-selected galaxies drawn from the MUNICS dataset. Our data cover the stellar mass range 10^10 <…
We use the Keck Deep Fields UGRI catalog of z~4, 3, and 2 UV-selected galaxies to study the evolution of the rest-frame 1700A luminosity density at high redshift. The ability to reliably constrain the contribution of faint galaxies is…