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20072025
most citedThe PHLEK Survey: A New Determination of the Primordial Helium Abundance

102 citations · 399 across the 15 of their papers we have counts for

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Showing 2020Show all

5 papers · 1 filter

astro-ph.GA2020

The stochastic enrichment of Population II stars

Louise Welsh, Ryan Cooke, Michele Fumagalli

We investigate the intrinsic scatter in the chemical abundances of a sample of metal-poor ([Fe/H]<-2.5) Milky Way halo stars. We draw our sample from four historic surveys and focu…

astro-ph.GA2020102 cited

The PHLEK Survey: A New Determination of the Primordial Helium Abundance

Tiffany Hsyu, Ryan J. Cooke, J. Xavier Prochaska +1

We present Keck NIRSPEC and Keck NIRES spectroscopy of sixteen metal-poor galaxies that have pre-existing optical observations. The near-infrared (NIR) spectroscopy specifically ta…

astro-ph.IM2020

PypeIt: The Python Spectroscopic Data Reduction Pipeline

J. Xavier Prochaska, Joseph F. Hennawi, Kyle B. Westfall +5

PypeIt is a Python package for semi-automated reduction of astronomical, spectroscopic data. Its algorithms build on decades-long development of previous data reduction pipelines b…

astro-ph.CO2020

A limit on Planck-scale froth with ESPRESSO

Ryan Cooke, Louise Welsh, Michele Fumagalli +1

Some models of quantum gravity predict that the very structure of spacetime is `frothy' due to quantum fluctuations. Although the effect is expected to be tiny, if these spacetime…

astro-ph.GA2020

A bound on the 12C/13C ratio in near-pristine gas with ESPRESSO

Louise Welsh, Ryan Cooke, Michele Fumagalli +1

Using science verification observations obtained with ESPRESSO at the Very Large Telescope (VLT) in 4UT mode, we report the first bound on the carbon isotope ratio 12C/13C of a qui…