Speaker
Description
Following evidence for an east-west elongated virial ring around the Coma galaxy cluster in ~220GeV VERITAS data, we search for corresponding signatures in >GeV $\gamma$-rays from Fermi-LAT, and in soft, ~0.1keV X-rays from ROSAT.
For the ring elongation and orientation inferred from VERITAS, we find a 3.4$\sigma$ LAT excess, and a >5$\sigma$ modelled signature in the ROSAT R1+R2 bands; both signals are maximized at approximately the expected ring parameters.
The intensities of the ROSAT, Fermi, and VERITAS signals are consistent with the virial shock depositing ~0.3%
of its energy over a Hubbble time in a nearly flat, p=-dN/dE~2.2 spectrum of relativistic electrons.
The steep angular profiles of the LAT and ROSAT signals suggest preferential accretion in the plane of the sky, as indicated by the distribution of neighboring large-scale structure.
The X-ray signal gauges the compression of cosmic-ray electrons as they are advected deeper into the cluster.
