4 papers
Towards a measurement of the primordial helium isotope ratio
Ryan J. Cooke, James W. Johnson, Pasquier Noterdaeme +4
We report the discovery of two metastable neutral helium (He I*) absorbers in the Milky Way, and use the upgraded CRyogenic InfraRed Echelle Spectrograph on the Very Large Telescop…
E-XQR-30: Evidence for an Increase in the Ionization State of Metal Absorbers from z~6 to z~2
Stephanie Rowlands, R. L. Davies, E. Ryan-Weber +15
We investigate the evolution of the ionization state of metal-enriched gas in and around galaxies near the epoch of reionization using a sample of 488 metal absorption systems at 4…
Unmixed metals: Variations in the enrichment of z~4 sub-damped Lyman alpha systems
Trystyn A. M. Berg, Louise A. Welsh, Ryan J. Cooke +4
The chemical abundance patterns of near-pristine objects provide important constraints on the properties of the first generations of stars in the Universe. We present the chemical…
An extremely metal-poor Lyman emitter candidate at revealed through absorption spectroscopy
Dominika ÄurovÄÃková, Anna-Christina Eilers, Robert A. Simcoe +10
We report the discovery of a Lyman emitter (LAE) candidate in the immediate foreground of the quasar PSO J158-14 at at a projected distance $\sim29\ {\rm…