相关论文: The AGN Hubble Diagram and Its Implications for Co…

Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above ~ 6x10^{19} electron volts and the positions of active galactic…

Heavily obscured accretion is believed to represent an important stage in the growth of supermassive black holes, and to play an important role in shaping the observed spectrum of the Cosmic X-ray Background (CXB). Hard X-ray (E$>$10 keV)…

Saulder et al [2019, A&A, 622, A83; arXiv:1811.11976] have performed a novel observational test of the local expansion of the Universe for the standard cosmology as compared to an alternative model with differential cosmic expansion. Their…

X-ray surveys provide the most efficient means for the detection of Active Galactic Nuclei (AGN). However, they face difficulties in detecting the most heavily obscured Compton-thick AGN. The BAT detector on board the Gehrels/Swift mission,…

According to the Hubble law, high redshift objects such as Quasar (QSOs), X-ray Active Galactic Nuclei (AGN) together with the Gamma Ray Burst (GRBs) are the fastest and farthest objects. These characteristics provides strong motivations…

Investigating the link between supermassive black hole and galaxy evolution requires careful measurements of the properties of the host galaxies. We perform simulations to test the reliability of a two-dimensional image-fitting technique to…

In modern cosmology, the rapid growth of high-precision observational data, along with significant theoretical advances, has intensified the challenge of identifying a robust, model-independent framework to probe the expansion history of…

We present the Advanced Camera for Surveys Active Galactic Nuclei (ACS-AGN) Catalog, a catalog of 2585 active galactic nucleus (AGN) host galaxies that are at redshifts 0.2<z<2.5 and that were imaged with the Hubble Space Telescope's…

The effect of curvature on the results of fractal analyses of the galaxy distribution is investigated. We show that, if the universe satisfies the criteria of a wide class of parabolic homogeneous models, the observers measuring the fractal…

Recent observations have revealed an interesting active galactic nuclei (AGN) subclass that shows strong activity at large scales ($\sim1$ kpc) but weaker at small scales ($<10$ pc), suggesting a strong change in the mass accretion rate of…

Active galactic nucleus (AGN) growth in disk-dominated, merger-free galaxies is poorly understood, largely due to the difficulty in disentangling the AGN emission from that of the host galaxy. By carefully separating this emission, we…

We present an updated and revised analysis of the relationship between the Hbeta broad-line region (BLR) radius and the luminosity of the active galactic nucleus (AGN). Specifically, we have carried out two-dimensional surface brightness…

In the late 1990's, observations of 93 Type Ia supernovae were analysed in the framework of the FLRW cosmology assuming these to be `standard(isable) candles'. It was thus inferred that the Hubble expansion rate is accelerating as if driven…

A previous analysis of starburst-dominated HII Galaxies and HII regions has demonstrated a statistically significant preference for the Friedmann-Robertson-Walker cosmology with zero active mass, known as the R_h=ct universe, over LCDM and…

We have incorporated the description of the X-ray properties of Active Galactic Nuclei (AGNs) into a semi-analytic model of galaxy formation, adopting physically motivated scaling laws for accretion triggered by galaxy encounters. Our model…

LambdaCDM, for the currently preferred cosmological density Omega_0 and cosmological constant Omega_Lambda, predicts that the Universe expansion decelerates from early times to redshift z~0.9 and accelerates at later times. On the contrary,…

Active Galactic Nuclei (AGN) produce a dominant fraction (~80%) of the Soft X-ray background (SXB) at photon energies 0.5<E<2 keV. If dust pervaded throughout the intergalactic medium, its scattering opacity would have produced diffuse…

We use three different data sets, specifically $H(z)$ measurements from cosmic chronometers, the HII-galaxy Hubble diagram, and reconstructed quasar-core angular-size measurements, to perform a joint analysis of three flat cosmological…

The merger of two or more galaxies can enhance the inflow of material from galactic scales into the close environments of Active Galactic Nuclei (AGN), obscuring and feeding the supermassive black hole (SMBH). Both recent simulations and…

As revealed by Hubble in 1928, our Universe is expanding. This discovery was fundamental to widening our horizons and our conception of space, and since then determining the rate at which our Universe is expanding has become one of the…