I am Andrej Dvornik, a postdoc at Ruhr-Universität Bochum.
Welcome on my personal website and blog. Here you can also find my research interests, publications, and CV. Please do get in touch!
+ Weak gravitational lensing + Large scale structure + Cosmology + Dark matter + Dark energy + Galaxy-dark matter connection + Halo model +
We measure the projected galaxy clustering and galaxy-galaxy lensing signals using the Galaxy And Mass Assembly (GAMA) survey and Kilo-Degree Survey (KiDS) to study galaxy bias. We use the concept of non-linear and stochastic galaxy biasing in the framework of halo occupation statistics to constrain the parameters of the halo occupation statistics and to unveil the origin of galaxy biasing. The bias function Γ is evaluated using the analytical halo model from which the scale dependence of Γ, and the origin of the non-linearity and stochasticity in halo occupation models can be inferred.
I have investigated possible signatures of halo assembly bias for spectroscopically selected galaxy groups from GAMA survey using weak lensing measurements from the KiDS survey. The GAMA galaxies are split into two samples, with similar mean halo masses but different spatial distributions of satellite galaxies. We find no evidence of halo assembly bias on galaxy group scales.