From string theory to Active Galactic Nuclei: searching for axions with X-rays

by Prof. Joseph Conlon (Oxford University)

Tuesday 16 May 2017, 16:15 → 17:15 Europe/Berlin

Auditorium (MPI Meeting rooms)

If string theory is a true theory of the world, one of its most generic features is the existence of axion-like particles (ALPs). ALPs would extend the Standard Model of particle physics with a new light, weakly coupled sector. Searches for ALPs offer a direction for progress orthogonal to that arising at the energy frontier. If they exist, ALPs interconvert with photons in coherent magnetic fields. The large-scale magnetic fields of the intracluster medium offer ideal environments for conversion, as ALPs would result in spectral modulations of Active Galactic Nuclei that are in or behind galaxy clusters. The existing X-ray archives offer tremendous reach in extending limits on ALPs beyond long-standing bounds from SN1987A. I describe constraints attainable with existing Chandra archives, and also the future reach that will be attained with the launch of ATHENA.