The Dark Energy Spectroscopic Instrument (DESI) survey will measure large-scale structures using quasars as direct tracers of dark matter in the redshift range...
Testing Einsteins Equivalence Principle and Its Cosmological Evolution from Quasar Gravitational Redshifts
We propose and apply a new test of Einsteins equivalence principle (EEP) based on the gravitational redshift induced by the central supermassive black hole of...
Testing Microvariability in Quasar Differential Light Curves Using Several Field Stars
Microvariability consists of small timescale variations of low amplitude in the photometric light curves of quasars and represents an important tool to...
We examine the ability to test the black hole no-hair theorem at the 10% level in this decade using the binary black hole in OJ287. In the test we constrain the...
Testing the Standard Model of Active Galactic Nuclei through Quasar Variability
The standard model of Active Galactic Nuclei (AGNs) predicts that Type 2 AGNs and Type 1 AGNs only differ in the orientation of a dust torus, which does or does...
The 11 Year Period in OJ 287 Revisited: Is It a True Long-Enduring Period?
The case of the possible 11 yr periodicity in the historical light curve of OJ 287 over a century of observations is examined critically largely independently...
The AGN contribution to mid-infrared surveys. X-ray counterparts of the mid-IR sources in the Lockman Hole and HDF-N
We provide constraints on the AGN contribution to the mid-IR extragalactic background light from a correlation analysis of deep X-ray and mid-IR observations in...
The ALHAMBRA survey: Discovery of a faint QSO at z = 5.41
Aims: We aim to illustrate the potentiality of the Advanced Large, Homogeneous Area, Medium-Band Redshift Astronomical (ALHAMBRA) survey to investigate the high...
The Average Size and Temperature Profile of Quasar Accretion Disks
We use multi-wavelength microlensing measurements of a sample of 10 image pairs from 8 lensed quasars to study the structure of their accretion disks. By using...