Radio relics: A joint analysis of simulations and surveys

MATTHIAS HOEFT; JAKOB GELSZINNIS; FRANCO VAZZA; SEBASTIÁN E. NUZA; GUSTAVO YEPES

Bolonia

Conferencia; The Broad Impact of Low Frequency Observing; 2017

ASTRON, INAF, RADIONET

Radio relics are sources of synchrotron emission found in downstream regions of galaxy cluster merger shocks. Diffusive shock acceleration paired with subsequent cooling has been considered as a comprehensive explanation for the origin of radio relics. Recent observational evidence is pointing to a more complex scenario. We present predictions from two large cosmological simulations (MUSIC-2 and Cosmic Web) on the radio relic findings of upcoming radio surveys. A novel approach is used to standardize and automate the extraction of the morphological features of radio relics. We first investigated how well these simulations agree with the NRAO VLA Sky Survey (NVSS). Our model reproduces the power, size, shape and alignment of radio relics with respect to their host clusters. Our analysis suggests a completeness of the NVSS relic sample of about 40% for fluxes above 10 mJy. In the simulations, we find a large number of marginally resolved radio gischt objects at redshifts >~ 0.4 that are not detected by current surveys. We predict that these objects with an extent of less than 1 arcmin can be identified with high-resolution surveys like LOFAR Tier I.