80 citations · 317 across the 19 of their papers we have counts for
11 papers · 1 filter
Measuring the fine structure constant on a white dwarf surface; a detailed analysis of Fe V absorption in G191-B2B
J. Hu, J. K. Webb, T. R. Ayres +12
The gravitational potential phi = GM/Rc^2 at the surface of the white dwarf G191-B2B is 10,000 times stronger than that at the Earth's surface. Numerous photospheric absorption fea…
A far-UV survey of three hot, metal-polluted white dwarf stars: WD0455-282, WD0621-376, and WD2211-495
S. P. Preval, M. A. Barstow, M. Bainbridge +7
Using newly obtained high-resolution data () from the \textit{Hubble Space Telescope}, and archival UV data from the \textit{Far Ultraviolet Spectroscopic E…
Constraining the magnetic field on white dwarf surfaces; Zeeman effects and fine structure constant variation
J. Hu, J. K. Webb, T. R. Ayres +12
White dwarf atmospheres are subjected to gravitational potentials around times larger than occur on Earth. They provide a unique environment in which to search for any possi…
Multi-wavelength observations of the EUV variable metal-rich white dwarf GD 394
David J. Wilson, Boris T. Gaensicke, Detlev Koester +13
We present new Hubble Space Telescope (HST) ultraviolet and ground-based optical observations of the hot, metal-rich white dwarf GD 394. Extreme-ultraviolet (EUV) observations in 1…
A Quantitative Comparison of Opacities Calculated Using the Distorted- Wave and -Matrix Methods
F. Delahaye, N. R. Badnell, C. P. Ballance +7
The present debate on the reliability of astrophysical opacities has reached a new climax with the recent measurements of Fe opacities on the Z-machine at the Sandia National Labor…
Hot DA white dwarf model atmosphere calculations: Including improved Ni PI cross sections
S. P. Preval, M. A. Barstow, N. R. Badnell +2
To calculate realistic models of objects with Ni in their atmospheres, accurate atomic data for the relevant ionization stages needs to be included in model atmosphere calculations…
Understanding the spectrum of the very hot DA white dwarf PG0948+534
S. P. Preval, M. A. Barstow
PG0948+534 is currently one of the hottest DA white dwarf stars, and is also one of the most mysterious. Attempts to model the sharp, deep absorption features of this star have bee…
Do the constants of nature couple to strong gravitational fields?
S. P. Preval, M. A. Barstow, J. B. Holberg +5
Recently, white dwarf stars have found a new use in the fundamental physics community. Many prospective theories of the fundamental interactions of Nature allow traditional constan…
A possible solution to the Lyman/Balmer line problem in hot DA white dwarfs
S. P. Preval, M. A. Barstow, N. R. Badnell +2
Arguably, the best method for determining the effective temperature () and surface gravity (log ) of a DA white dwarf is by fitting the Hydrogen Lyman and Balm…
A comprehensive near and far ultraviolet spectroscopic study of the hot DA white dwarf G191-B2B
Simon P. Preval, Martin A. Barstow, Jay B. Holberg +1
We present a detailed spectroscopic analysis of the hot DA white dwarf G191-B2B, using the best signal to noise, high resolution near and far UV spectrum obtained to date. This is…
Towards a standardised line list for G191-B2B, and other DA type objects
Simon P. Preval, Martin A. Barstow, Jay B. Holberg +1
We present a comprehensive analysis of the far UV spectrum of G191-B2B over the range of 900-1700Å using co-added data from the FUSE and STIS archives. While previous identificatio…