Related papers: Low redshift calibration of the Amati relation usi…
In this paper we examine how well galaxies and intra-cluster gas trace the gravitational potential of clusters. Utilizing mass profiles derived from gravitational lensing and X-ray observations, coupled with measured galaxy velocities, we…
Gamma ray burst (GRBs) can be used to constrain cosmological parameters from medium up to very high redshift. These powerful systems could be the further reliable distance indicators after SNeIa supernovae. We consider GRBs samples to…
Galaxy clusters are the largest gravitationally bound objects in the universe and may be suitable targets for indirect dark matter searches. With 85 months of Fermi-LAT Pass 8 publicly available data, we analyze the gamma-ray emission in…
We present the first measurements of the X-ray size-temperature (ST) relation in intermediate redshift (z~0.30) galaxy clusters. We interpret the local ST relation (z~0.06) in terms of underlying scaling relations in the cluster dark matter…
We investigate the clustering of afterglow light curves observed at X-ray and optical wavelengths. We have constructed a sample of 61 bursts with known distance and X-ray afterglow. GRB sources can be divided in three classes, namely…
We analyse the spatial clustering properties of a new catalogue of very rich galaxy clusters selected from the APM Galaxy Survey. These clusters are of comparable richness and space density to Abell Richness Class $\geq 1$ clusters, but…
We study the redshift space correlation function of galaxy clusters for observational samples constructed in different surveys. We explore correlation amplitudes, pairwise velocity distributions and bias factors. Systematics in cluster…
We present a comprehensive study of the morphological properties of 42 gamma-ray burst (GRB) host galaxies imaged with the Hubble Space Telescope in the optical band. The purpose of this study is to understand the relation of GRBs to their…
Recent evidence appears to link gamma-ray bursts (GRBs) to star-forming regions in galaxies at cosmological distances. If short-lived massive stars are the progenitors of GRBs, the rate of events per unit cosmological volume should be an…
We investigate the anisotropic stress parameter, $\eta=\Psi/\Phi$, defined as the ratio of the gravitational potentials in the linearly perturbed Friedmann-Lema\^itre Robertson-Walker metric, as a probe of deviations from general relativity…
Redshift-space distortions in the clustering of galaxy clusters provide a novel probe to test the gravity theory on cosmological scales. The aim of this work is to derive new constraints on the linear growth rate of cosmic structures from…
We have measured the angular correlation function w(theta) for a sample of 871 Lyman-break galaxies (LBGs) at z=3. Fitting a power-law to a weighted average of w(theta) from 5 fields, we find the amplitude to be A_w=2 arcsec^{\beta} and the…
We present a new investigation of the mass-temperature (\MTrelation) relation of 22 nearby clusters based on the analysis of their ROSAT X-ray surface brightness profiles ($S_{X}(r)$) and their ASCA emission weighted temperatures. Two…
Gamma-ray bursts (GRBs) have been regarded as standard candles at very high redshift for cosmology research. We have proposed a new method to calibrate GRB distance indicators with Type Ia supernova (SNe Ia) data in a completely…
We measure the two-point angular correlation function of a sample of 4,289,223 galaxies with r < 19.4 mag from the Sloan Digital Sky Survey as a function of photometric redshift, absolute magnitude and colour down to M_r - 5log h = -14 mag.…
Thanks to more and more gamma-ray bursts with measured redshift and extended emission detected by the recent space telescopes, it is urgent and possible to check whether those previous energy correlations still satisfy for the particular…
In recent years there has been considerable activity in using gamma-ray bursts as cosmological probes for determining global cosmological parameters complementing results from type Ia supernovae and other methods. This requires a…
A recent spectrum of the optical afterglow of GRB 970508 suggests that gamma-ray bursts (GRBs) are cosmological in origin and it is of crucial importance to derive an accurate distance to each burst. If GRBs occur near their host galaxies…
The on-going X-ray all-sky survey with the eROSITA instrument will yield large galaxy cluster samples, which will bring strong constraints on cosmological parameters. In particular, the survey holds great promise to investigate the tension…
We investigate the relationship between soft \xray luminosity and mass for low redshift clusters of galaxies by comparing observed number counts to expectations of $\Lambda$CDM cosmologies. We use a three-parameter model for the conditional…