A5055087138- Pulsars and Gravitational Waves Research
- Geophysics and Sensor Technology
- Astrophysical Phenomena and Observations
- High-pressure geophysics and materials
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Gamma-ray bursts and supernovae
- Digital Transformation in Industry
- Laser-Plasma Interactions and Diagnostics
- Distributed and Parallel Computing Systems
- Stellar, planetary, and galactic studies
- Superconducting Materials and Applications
- Maritime and Coastal Archaeology
- Particle Accelerators and Free-Electron Lasers
- Solar and Space Plasma Dynamics
- Laser-Matter Interactions and Applications
- Particle accelerators and beam dynamics
- Science Education and Perceptions
Los Alamos National Laboratory
2014-2022
Lawrence Livermore National Laboratory
2022
University of Rochester
2022
Energetics (United States)
2022
Cornell University
2007
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 condensation can significantly affect thermal emission from isolated stars, and lead to formation of charge-depleted acceleration zone ("vacuum gap") magnetosphere stellar polar cap. Using latest results on cohesive property matter, we quantitatively determine conditions for vacuum gap stars. We find that occur if energy kT is less...
Hohlraums are hollow cylindrical cavities with high-Z material walls used to convert laser energy into uniform x-ray radiation drives for inertial confinement fusion capsule implosions and high density physics experiments. Credible computational modeling of hohlraums requires detailed coupling physics, hydrodynamics, transport, heat atomic physics. We report on improvements Los Alamos National Laboratory's xRAGE radiation-hydrodynamics code in order enable hohlraum modeling. xRAGE's Eulerian...
X-ray observations of quiescent binaries have the potential to provide insight into structure and composition neutron stars. EXO 0748-676 had been actively accreting for over 24 yr before its outburst ceased in late 2008. Subsequent monitoring revealed a gradual decay thermal emission that can be attributed cooling accretion-heated star crust. In this work, we report on new Chandra Swift extend ~5 post-outburst. We find temperature remained at ~117 eV between 2009 2011, but decreased ~110...
Recent observations of thermally emitting isolated neutron stars revealed spectral features that could be interpreted as radiative transitions He in a magnetized star atmosphere. We present Hartree–Fock calculations the polarization-dependent photoionization cross-sections atom strong magnetic fields ranging from 1012 to 1014 G. Convenient fitting formulae for are given along with related oscillator strengths various bound–bound transitions. The effects finite nucleus mass on absorption...
Abstract We present a study of how low-temperature accreted atmosphere influences the emitted X-ray spectrum neutron star. The models and spectra were computed with Zcode, multigroup radiation transfer code developed at Los Alamos National Laboratory. Though underlying hot star behaves as blackbody, shifts peak away from blackbody toward higher energies, producing an similar to dilute blackbody. Quantifying effects this will remove source uncertainty in observations better constrain...