We present a sample of sources with convex radio spectra peaking at frequencies above a few GHz, known as ``High Frequency Peakers" (HFPs). A ``bright" sample...

We propose a systematic study of the environments of a representative sample of Radio Loud Quasars (RLQ) and Radio Quiet Quasars (RQQ) in two different redshift...

High-quality Extragalactic Legacy-field Monitoring (HELM) is a long-term observing program that photometrically monitors several well-studied extragalactic...

In order to definitely prove the claim by Claeskens et al. (1996A&A...305L...9C) that J03.13 is a doubly imaged quasar, WFPC2 direct imaging and FOS...

The authors have studied the IRAS extragalactic catalogue (Lonsdale et al., 1985), with the aim of reliably identifying quasi-stellar objects. Using the best...

The Dark Energy Spectroscopic Instrument (DESI) cosmology survey includes a Bright Galaxy Survey (BGS), which will yield spectra for over 10 million bright...

Using the predictions of the Lynden Bell/Hills model of the energy source of QSO's in which discrete packets of matter (e.g., stars) are converted into...

We present a combined galaxy-quasar approach to template-fitting photometric redshift techniques and show the method to be a powerful one. The code (IMPZ) is...

Assuming a gravitational origin for the Fe iiiλλ2039-2113 redshift and using microlensing based estimates of the size of the region emitting this feature, we...