High signal-to-noise spectra of the H-beta region of eight radio-loud quasars are presented in an investigation seeking evidence for the emission of this line...
Quasar Microlensing Statistics and Flux-ratio Anomalies in Lens Models
Precise lens modeling is a critical step in time delay studies of multiply imaged quasars, which are key for measuring some important cosmological parameters...
Quasar Milli-lensing and Cold Dark Matter (TNG50) Subhaloes. I. Image Splitting
We use numerical mass density profiles from the TNG50 simulation to study the impact of gravitational milli-lensing by dark matter subhaloes on the images of...
Quasars as a Tracer of Large-scale Structures in the Distant Universe
We study the dependence of the number density and properties of quasars on the background galaxy density using the currently largest spectroscopic data sets of...
Quasars with flare/eclipse-like variability identified in ZTF
Active galactic nuclei (AGNs) are known to exhibit optical/ultraviolet variability and most of them can be well modelled by the damped random walks. Physical...
Quasars with P v broad absorption in BOSS data release 9
Broad absorption lines (BALs) found in a significant fraction of quasar spectra identify high-velocity outflows that might be present in all quasars and could...
Quasi-periodic behaviour in the optical and γ-ray light curves of blazars 3C 66A and B2 1633+38
We report on quasi-periodic variability found in two blazars included in the Steward Observatory Blazar Monitoring data sample: the BL Lac object 3C 66A and the...
Quasi-periodic X-ray eruptions years after a nearby tidal disruption event
Quasi-periodic eruptions (QPEs) are luminous bursts of soft X-rays from the nuclei of galaxies, repeating on timescales of hours to weeks 1–5. The mechanism...