We have used William Herschel Telescope/INGRID Ks images on two high-latitude fields, the Coppi and Groth strips, to obtain galaxy number counts over ~180...
The COSMOS Survey is currently mapping 0.5 deg2 of sky in optical and near-IR bands to definesamples of compact galaxies at high redshift for spectroscopic...
Large Scale Absorbers in the Environment of High-z Radio-Galaxies
We discuss a number of interesting questions that arise from studies of extended absorbers observed in high redshift radio-galaxies. We propose to carry out 2-D...
Large SDSS Quasar Groups and their Statistical Significance
We use a volume-limited sample of quasars in the Sloan Digital Sky Survey (SDSS) DR7 quasar catalog to identify quasar groups and address their statistical...
Lensed Type Ia Supernova "Encore" at z = 2: The First Instance of Two Multiply Imaged Supernovae in the Same Host Galaxy
A bright (m F150W,AB = 24 mag), z = 1.95 supernova (SN) candidate was discovered in JWST/NIRCam imaging acquired on 2023 November 17. The SN is quintuply imaged...
Lensing without borders - I. A blind comparison of the amplitude of galaxy-galaxy lensing between independent imaging surveys
Lensing without borders is a cross-survey collaboration created to assess the consistency of galaxy-galaxy lensing signals (ΔΣ) across different data sets and...
Limiting the Abundance of LIGO/Virgo Black Holes with Microlensing Observations of Quasars of Finite Size
We present a simple but general argument that strongly limits the abundance of primordial black holes (PBHs) (or other unknown population of compact objects)...
Limits on Hot Intracluster Gas Contributions to the Tenerife Temperature Anisotropy Map
We limit the contribution of the hot intracluster gas, by means of the Sunyaev-Zeldovich effect, to the temperature anisotropies measured by the Tenerife...
Lines in the cosmic microwave background spectrum from the epoch of cosmological helium recombination
The main goal of this work is to calculate the contributions of bound-bound transitions of helium to the cosmological recombination spectrum. We show that...