105 citations · 616 across the 15 of their papers we have counts for
15 papers
Modeling X-ray Bursting Neutron Star Atmospheres
Lourenzo Colleyn, Zach Medin, Alan Calder
We present a verification of a computational model, developed at the Los Alamos National Laboratory (LANL) for simulating radiation transfer in X-ray bursting neutron star atmosphe…
Model Atmospheres for X-ray Bursting Neutron Stars
Zach Medin, Marina von Steinkirch, Alan C. Calder +3
The hydrogen and helium accreted by X-ray bursting neutron stars is periodically consumed in runaway thermonuclear reactions that cause the entire surface to glow brightly in X-ray…
A Survey of Chemical Separation in Accreting Neutron Stars
Ryan Mckinven, Andrew Cumming, Zach Medin +1
The heavy element ashes of rp-process hydrogen and helium burning in accreting neutron stars are compressed to high density where they freeze, forming the outer crust of the star.…
Time-dependent, compositionally driven convection in the oceans of accreting neutron stars
Zach Medin, Andrew Cumming
We discuss the effect of chemical separation as matter freezes at the base of the ocean of an accreting neutron star, and the subsequent enrichment of the ocean in light elements a…
Probing the Crust of the Neutron Star in EXO 0748-676
N. Degenaar, Z. Medin, A. Cumming +7
X-ray observations of quiescent X-ray binaries have the potential to provide insight into the structure and the composition of neutron stars. EXO 0748-676 had been actively accreti…
A signature of chemical separation in the cooling curves of transiently accreting neutron stars
Zach Medin, Andrew Cumming
We show that convection driven by chemical separation can significantly affect the cooling curves of accreting neutron stars after they go into quiescence. We calculate the thermal…
Direct MD simulation of liquid-solid phase equilibria for three-component plasma
J. Hughto, C. J. Horowitz, A. S. Schneider +3
The neutron rich isotope 22Ne may be a significant impurity in carbon and oxygen white dwarfs and could impact how the stars freeze. We perform molecular dynamics simulations to de…
Compositionally-driven convection in the oceans of accreting neutron stars
Zach Medin, Andrew Cumming
We discuss the effect of chemical separation as matter freezes at the base of the ocean of an accreting neutron star, and argue that the retention of light elements in the liquid a…
Crystallization of classical multi-component plasmas
Zach Medin, Andrew Cumming
We develop a method for calculating the equilibrium properties of the liquid-solid phase transition in a classical, ideal, multi-component plasma. Our method is a semi-analytic cal…
Pair cascades in the magnetospheres of strongly-magnetized neutron stars
Zach Medin, Dong Lai
We present numerical simulations of electron-positron pair cascades in the magnetospheres of magnetic neutron stars for a wide range of surface fields (B_p = 10^{12}--10^{15} G), r…
Condensed Surfaces of Magnetic Neutron Stars, Thermal Surface Emission, and Particle Acceleration Above Pulsar Polar Caps
Zach Medin, Dong Lai
For sufficiently strong magnetic fields and/or low temperatures, the neutron star surface may be in a condensed state with little gas or plasma above it. Such surface condensation…
Radiative transitions of the helium atom in highly magnetized neutron star atmospheres
Zach Medin, Dong Lai, Alexander Y. Potekhin
Recent observations of thermally emitting isolated neutron stars revealed spectral features that could be interpreted as radiative transitions of He in a magnetized neutron star at…
Cohesive property of magnetized neutron star surfaces: Computations and implications
Zach Medin, Dong Lai
The cohesive energy of condensed matter in strong magnetic fields is a fundamental quantity characterizing magnetized neutron star surfaces. The cohesive energy refers to the energ…
Density-Functional-Theory Calculations of Matter in Strong Magnetic Fields: II. Infinite Chains and Condensed Matter
Zach Medin, Dong Lai
We present new, ab initio calculations of the electronic structure of one-dimensional infinite chains and three-dimensional condensed matter in strong magnetic fields ranging from…
Density-Functional-Theory Calculations of Matter in Strong Magnetic Fields: I. Atoms and Molecules
Zach Medin, Dong Lai
We present new ab initio calculations of the electronic structure of various atoms and molecules in strong magnetic fields ranging from B=10^12 G to 2x10^15 G, appropriate for radi…