Green Bank and Effelsberg Radio Telescope Searches for Axion Dark Matter Conversion in Neutron Star Magnetospheres
Abstract
Axion dark matter (DM) may convert to radio-frequency electromagnetic radiation in the strong magnetic fields around neutron stars. The radio signature of such a process would be an ultranarrow spectral peak at a frequency determined by the mass of the axion particle. We analyze data we collected from the Robert C. Byrd Green Bank Telescope in the L band and the Effelsberg 100-m Telescope in the L band and S band from a number of sources expected to produce bright signals of axion-photon conversion, including the Galactic center of the Milky Way and the nearby isolated neutron stars RX J0720.4-3125 and RX J0806.4-4123. We find no evidence for axion DM and are able to set constraints on the existence of axion DM in the highly motivated mass range between ∼5 and 11 μ eV with the strongest constraints to date on axions in the ∼10 - 11 μ eV range.
- Publication:
-
Physical Review Letters
- Pub Date:
- October 2020
- DOI:
- 10.1103/PhysRevLett.125.171301
- arXiv:
- arXiv:2004.00011
- Bibcode:
- 2020PhRvL.125q1301F
- Keywords:
-
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Phenomenology
- E-Print:
- 7+20 pages, 2+17 figures, Supplementary Data at http://github.com/joshwfoster/RadioAxionSearch