X-Ray Signatures of Axion Conversion in Magnetic White Dwarf Stars

2019/03/31 by Christopher Dessert, Andrew J. Long, Benjamin R. Safdi · 2 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Axion #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Galaxy #Luminosity #Luminosity function #Observable #Photon #Physics #Stars #White dwarf #astro-ph.HE #astro-ph.SR #hep-ph

paper · pdf · doi:10.1103/physrevlett.123.061104

published as Phys. Rev. Lett. 123, 061104 (2019) · 6+10 pages, 2+8 figures, version published in PRL

openalex publication_date 2019/08/07 · arxiv created 2021/03/01 · arxiv updated 2021/03/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

White dwarf (WD) stars may radiate keV-energy axions produced in their stellar cores. This has been extensively studied as an extra channel by which WDs may cool, with some analyses even suggesting that axions can help explain the observed WD luminosity function. We show that the radiated axions may convert into x rays in the strong magnetic fields surrounding the WDs, leading to observable x-ray signatures. We use Suzaku observations of the WD RE J0317-853 to set the strongest constraints to date on the combination of the axion-electron (g_aee) times axion-photon (g_aγγ) couplings, and we show that dedicated observations of magnetic WDs by telescopes such as Chandra, XMM-Newton, and NuSTAR could increase the sensitivity to |g_aeeg_aγγ| by over an order of magnitude, allowing for a definitive test of the axionlike-particle explanation of the stellar cooling anomalies.

Citations

• Magnetic White Dwarfs
• CAST constraints on the axion-electron coupling
• Revisiting the SN1987A gamma-ray limit on ultralight axion-like particles
• A simple solution to the strong CP problem with a harmless axion
• Axions and the white dwarf luminosity function
• Photometric variability of the unique magnetic white dwarf GD 356
• Axions and the Cooling of White Dwarf Stars
• Cooling Sequences and Color‐Magnitude Diagrams for Cool White Dwarfs with Hydrogen Atmospheres
• Broadband and Resonant Approaches to Axion Dark Matter Detection
• The HAYSTAC Axion Search Analysis Procedure
• Radio telescope search for the resonant conversion of cold dark matter axions from the magnetized astrophysical sources
• Gaia Data Release 2
• Review of Particle Physics
• String axiverse

Cited by

• Investigating the light curve variation of magnetic white dwarfs induced by the axion-photon conversion
• Searching for the QCD Dark Matter Axion