Related papers: Quasars as a tracer of large-scale structures in t…
For the first time spectroscopic galaxy redshift surveys are reaching the scales where galaxies can be studied together with the nearest quasars. This gives an opportunity to study the dependence between the activity of a quasar and its…
We investigate the spatial clustering of galaxies around quasars at redshifts from 0.6 to 1.2 using the photometric data from Sloan Digital Sky Survey (SDSS) Stripe 82. The quasar and galaxy cross-correlation functions are measured through…
The impact of quasars on their galaxy neighbors is an important factor in the understanding of the galaxy evolution models. The aim of this work is to characterize the close environments of quasars at low redshift (z$<$0.2) with the most…
We present a new approach to analysing the dependence of quasar variability on rest-frame wavelengths. We exploited the spectral archive of the Sloan Digital Sky Survey (SDSS) to create a sample of more than 9000 quasars in the Stripe 82.…
We study the cosmic web at redshifts 1.0 <= z <= 1.8 using quasar systems based on quasar data from the SDSS DR7 QSO catalogue. Quasar systems were determined with a friend-of-friend (FoF) algorithm at a series of linking lengths. At the…
Quasars,asextremelyluminousanddistantspecialcelestialbodiesintheuniverse,aredrivenbyacomplexsystemcomposedof supermassiveblackholesandsurroundingaccretiondisks.Thispaperadoptsatime-domainobservationstrategyandcombines the analysis of light…
The impact of quasars on their galaxy neighbours is an important factor in the understanding of galaxy evolution models. The aim of this work is to characterize the intermediate-scale environments of quasars at low redshift (z $<$ 0.2) with…
We search for the most suitable set of cosmological parameters that describes the observable universe. The search includes the possibility of quintessential flat universes, i.e., the analysis is restricted to the determination of the…
We trace the cosmic web at redshifts 1.0 <= z <= 1.8 using the quasar data from the SDSS DR7 QSO catalogue (Schneider et al. 2010). We apply a friend-of-friend (FoF) algorithm to the quasar and random catalogues to determine systems at a…
The relationship between quasars and their galaxy environment is important for understanding the evolution of galaxies and supermassive black holes, but it is not fully understood. We perform a wide and deep exploration of the environment…
Quasars are effective tracers of the large-scale distribution of galaxies at high redshift thanks to their high luminosity and dedicated surveys. Previous studies have shown that quasars exhibit a bias similar to that of rich groups,…
We analyse the environment of low redshift, z < 0.2, SDSS quasars using the spectral and photometric information of galaxies from the Sloan Digital Sky Survey Third Data Release (SDSS-DR3). We compare quasar neighbourhoods with field and…
In this thesis, I present an investigation into the environments of quasars with respect to galaxy clusters, and environment evolution with redshift and luminosity. The orientation of the quasar with respect to the major axis of the closest…
We use 62,185 quasars from the Sloan Digital Sky Survey DR5 sample and standard virial mass scaling laws based on the widths of H beta, Mg II, and C IV lines and adjacent continuum luminosities to explore the maximum mass of quasars as a…
Using a homogenous sample of 38,208 quasars with a sky coverage of $4000 {\rm deg^2}$ drawn from the SDSS Data Release Five quasar catalog, we study the dependence of quasar clustering on luminosity, virial black hole mass, quasar color,…
We present a simple model for the relationship between quasars, galaxies, and dark matter halos from 0.5<z<6. In the model, black hole (BH) mass is linearly related to galaxy mass, and galaxies are connected to dark matter halos via…
The non-Euclidean geometry of spacetime induces an anisotropy in the apparent correlation function of high-redshift quasars. This effect can constrain the cosmological constant \Lambda independent of any assumptions about evolution of…
High-redshift quasars have been an excellent tracer to study the astrophysics and cosmology at early Universe. Using 577 spectroscopically confirmed high-redshift quasars and 1,796 highly reliable photometric quasar candidates (all with…
We provide a simple theoretical model for the quasar luminosity function at high redshifts that naturally reproduces the statistical properties of the luminous SDSS quasar sample at redshifts z~4.3 and z>5.7. Our model is based on the…
This review attempts to describe developments in the fields of quasar and quasar host galaxies in the past five. In this time period, the Sloan and 2dF quasar surveys have added several tens of thousands of quasars, with Sloan quasars being…