  We further study a scenario in which a 3.55 keV X-ray line arises from decay
of dark matter to an axion-like particle (ALP), that subsequently converts to a
photon in astrophysical magnetic fields. We perform numerical simulations of
Gaussian random magnetic fields with radial scaling of the magnetic field
magnitude with the electron density, for both cool-core `Perseus' and
non-cool-core `Coma' electron density profiles. Using these, we quantitatively
study the resulting signal strength and morphology for cool-core and
non-cool-core clusters. Our study includes the effects of fields of view that
cover only the central part of the cluster, the effects of offset pointings on
the radial decline of signal strength and the effects of dividing clusters into
annuli. We find good agreement with current data and make predictions for
future analyses and observations.
