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Constraining the magnetic field on white dwarf surfaces; Zeeman effects and fine structure constant variation
- Source :
- Mon.Not.Roy.Astron.Soc., Mon.Not.Roy.Astron.Soc., 2019, 485 (4), pp.5050-5058. ⟨10.1093/mnras/stz739⟩
- Publication Year :
- 2019
- Publisher :
- HAL CCSD, 2019.
-
Abstract
- White dwarf atmospheres are subjected to gravitational potentials around $10^5$ times larger than occur on Earth. They provide a unique environment in which to search for any possible variation in fundamental physics in the presence of strong gravitational fields. However, a sufficiently strong magnetic field will alter absorption line profiles and introduce additional uncertainties in measurements of the fine structure constant. Estimating the magnetic field strength is thus essential in this context. Here we model the absorption profiles of a large number of atomic transitions in the white dwarf photosphere, including first-order Zeeman effects in the line profiles, varying the magnetic field as a free parameter. We apply the method to a high signal-to-noise, high-resolution, far-ultraviolet HST/STIS spectrum of the white dwarf G191-B2B. The method yields a sensitive upper limit on its magnetic field of $B < 2300$ Gauss at the $3\sigma$ level. Using this upper limit we find that the potential impact of quadratic Zeeman shifts on measurements of the fine structure constant in G191-B2B is 4 orders of magnitude below laboratory wavelength uncertainties.<br />Comment: 10 pages, 5 figures
- Subjects :
- Physics
atomic processes
Library science
FOS: Physical sciences
Astronomy and Astrophysics
line: profiles
General Relativity and Quantum Cosmology (gr-qc)
magnetic fields
01 natural sciences
General Relativity and Quantum Cosmology
Royal Commission
Scholarship
Astrophysics - Solar and Stellar Astrophysics
Space and Planetary Science
0103 physical sciences
[PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc]
Astrophysics::Solar and Stellar Astrophysics
010306 general physics
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
010303 astronomy & astrophysics
Data archive
Solar and Stellar Astrophysics (astro-ph.SR)
white dwarfs
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Mon.Not.Roy.Astron.Soc., Mon.Not.Roy.Astron.Soc., 2019, 485 (4), pp.5050-5058. ⟨10.1093/mnras/stz739⟩
- Accession number :
- edsair.doi.dedup.....7e49f2ed64efefe901e98a506460bfae
- Full Text :
- https://doi.org/10.1093/mnras/stz739⟩