▪ Abstract Deep surveys of the cosmic X-ray background are reviewed in the context of
observational progress enabled by the Chandra X-Ray Observatory and the X-Ray Multi …

As the sky in the microwave band is dominated by a cosmic background, so too is the X-ray
sky. In this report, the experimental approach used for measuring the X-ray background is …

Context. The AGN bolometric correction is a key element for understanding black hole (BH)
demographics and computing accurate BH accretion histories from AGN luminosities …

The recent Hubble constant, H 0, tension is observed between the value of H 0 from the
cosmic microwave background (CMB) and Type Ia supernovae (SNe Ia). It is a decade since …

We present a new catalogue of∼ 2400 optically selected quasars with spectroscopic
redshifts and X-ray observations from either Chandra or XMM–Newton. The sample can be …

The longstanding search for the cosmological model that best describes the Universe has
been made more intriguing since the recent discovery of the Hubble constant, H 0, tension …

Based on the assumption that quasars (QSOs) and gamma-ray bursts (GRBs) represent
standardizable candles, we provide evidence that the Hubble constant H 0 adopts larger …

Quasar masses are investigated assuming that accretion on to massive black holes is the
ultimate source of energy produced by quasars. Lower limit for the total energy emitted and …

Cosmological models and their parameters are widely debated because of theoretical and
observational mismatches of the standard cosmological model, especially the current …

The current standard model of cosmology successfully describes a variety of measurements,
but the nature of its main ingredients, dark matter and dark energy, remains unknown. is a …