21-26 July 2014
Renold Building
Europe/London timezone
Home > Timetable > Session details > Contribution details
PDF | XML | iCal

A 3.55 keV Photon Line and its Morphology from a 3.55 keV ALP Line

Presented by Mr. Markus RUMMEL on 25 Jul 2014 from 16:50 to 17:10
Type: Alternative Theories
Track: Alternative Theories


Galaxy clusters can efficiently convert axion-like particles (ALPs) to photons. We propose that the recently claimed detection of a 3.55--3.57 keV line in the stacked spectra of a large number of galaxy clusters and the Andromeda galaxy may originate from the decay of either a scalar or fermionic 7.1 keV dark matter species into an axion-like particle (ALP) of mass ma≲6⋅10−11 eV, which subsequently converts to a photon in the cluster magnetic field. In contrast to models in which the photon line arises directly from dark matter decay or annihilation, this can explain the anomalous line strength in the Perseus cluster. As axion-photon conversion scales as B2 and cool core clusters have high central magnetic fields, this model can also explains the observed peaking of the line emission in the cool cores of the Perseus, Ophiuchus and Centaurus clusters, as opposed to the much larger dark matter halos. We describe distinctive predictions of this scenario for future observations.


Location: Renold
Room: F1

Primary authors