4 citations · 6 across the 11 of their papers we have counts for
12 papers
The LBT Y Project VI: Gas-Phase Chemical Abundance Patterns of Metal-Poor Nebulae
Noah S. J. Rogers, Evan D. Skillman, Richard W. Pogge +7
Through a combined rest-optical and NIR observing campaign, the Large Binocular Telescope Primordial He Abundance () Project has delivered a precision measurement of $Y_…
Evidence for Enhanced Helium Enrichment from Asteroseismology
Miqaela K. Weller, Marc H. Pinsonneault, Jennifer A. Johnson +1
The helium abundance of a star has a dramatic effect on luminosity, internal structure, and evolutionary timescales, yet direct helium measurements are unavailable for most stars.…
Constraints on the Galactic Chemical Evolution of
Miqaela K. Weller, David H. Weinberg
We examine the galactic chemical evolution (GCE) of in one-zone and multi-zone models, with particular attention to the stellar yields and GCE parameters that can repro…
The LBT Project V: Cosmological Implications of a New Determination of Primordial He
Tsung-Han Yeh, Keith A. Olive, Brian D. Fields +5
The primordial abundance of He plays a central role in big-bang nucleosynthesis (BBN) and in the cosmic microwave background (CMB). The LBT Project's new measuremen…
The LBT Y Project IV: A New Value of the Primordial Helium Abundance
Erik Aver, Evan D. Skillman, Richard W. Pogge +7
We present a new determination of the primordial helium abundance based on new, high-quality Large Binocular Telescope (LBT) observations of 54 metal-poor H II regions. These regio…
The LBT Project III: LUCI Spectra of Metal-Poor Nebulae
Miqaela K. Weller, Richard W. Pogge, Evan D. Skillman +6
Accurately determining the elemental abundances of a low metallicity nebula strongly depends on measuring the density (n) and temperature (T) of the gas. Because these two…
The LBT Project I: An Improved Determination of the Primordial Helium Abundance -- Project Description, Sample Selection, Observations, and Methodology
Evan D. Skillman, Richard W. Pogge, Erik Aver +9
Extremely low metallicity HII regions have been observed with the goal of determining the primordial helium abundance (). , combined with standard big bang nu…
The LBT Project II: MODS Spectra, Physical Conditions, and Oxygen Abundances in Local Metal-Poor Nebulae
Noah S. J. Rogers, Evan D. Skillman, Richard W. Pogge +7
Empirically measuring the primordial He mass fraction, , requires a significant number of low-metallicity nebulae with direct constraints on He/H and O/H abundances. Thi…
Metals versus Non-metals: Chemical Evolution of Hydrogen and Helium Isotopes in the Milky Way
James W. Johnson, Miqaela K. Weller, Ryan J. Cooke
Star formation drives changes in the compositions of galaxies, fusing H and He into heavier nuclei. This paper investigates the differences in abundance evolution between metal and…
The Milky Way Radial Metallicity Gradient as an Equilibrium Phenomenon: Why Old Stars are Metal-Rich
James W. Johnson, David H. Weinberg, Guillermo A. Blanc +12
Metallicities of both gas and stars decline toward large radii in spiral galaxies, a trend known as the radial metallicity gradient. We quantify the evolution of the metallicity gr…
Modeling the Galactic Chemical Evolution of Helium
Miqaela K. Weller, David H. Weinberg, James W. Johnson
We examine the galactic chemical evolution (GCE) of He in one-zone and multi-zone models, with particular attention to theoretical predictions and empirical constraints on IMF-…
Mapping Progenitors of Binary Black Holes and Neutron Stars with Binary Population Synthesis
Miqaela K. Weller, Jennifer A. Johnson
The first directly observed gravitational wave event, GW150914, featuring the merger of two massive black holes, highlighted the need to determine how these systems of compact remn…