  New multi-wavelength (radio, optical & X-rays) observational evidences are
presented which show that the nearby (z=0.046), rich cluster of galaxies Abell
3376 is experiencing a major event of binary subcluster merger. The key
evidence is the discovery of a pair of large, optically unidentified diffuse
radio sources (`arcs'), symmetrically located about 2.6 h_{50}^{-1} Mpc apart
at the opposite ends of the hot intra-cluster gas mapped by ROSAT in X-rays. It
is argued that the gas-dynamical shock-waves, which occur naturally during
cluster formation, are accelerating charged particles (cosmic rays) to
relativistic energies, leading to synchrotron emission from the megaparsec
scale radio arcs. If this is so, cluster Abell 3376 would also be a potential
source capable of accelerating cosmic ray particles upto ultra-high energies
(UHECR) of E_{max} ~ 10^{18-19} eV. Thus this cluster is an excellent test-bed
for understanding the physics of merger shocks and origin of enigmatic UHECR
particles in structure formation process. Hence, Abell 3376 provides unique
oppurtunities for further multi-wavelength observations with ground and
space-borne observatories.
