Bounds on Axion-like Particles from X-ray observations of AGNs and quasars
Abstract
Axion-like particles are a well-motivated extension of the Standard Model. They arise generically in string theory and they can be (part of) dark matter. Axion-like particles can induce localised oscillatory modulations in the spectra of photon sources passing through astrophysical magnetic fields, in particular through magnetic fields in galaxy clusters. By the absence of modulations in AGN/Quasar spectra (in particular from observations of the central AGN of NGC1275 in the Perseus Cluster) we are able to place world-leading bounds on light axion-like particles: g_{aγγ}< 1.4 - 4.0 × 10^{-12}GeV^{-1} for m_{axion} < 10^{-12}eV. I will present how we obtain these bounds from Chandra observations, how they compare to direct (upcoming) experimental searches (e.g. IAXO) and how future observations (for instance with Athena) could improve these bounds. This talk will be based on 1605.01043 and work in progress to be published soon.
- Publication:
-
The X-ray Universe 2017
- Pub Date:
- October 2017
- Bibcode:
- 2017xru..conf..120K